pen

Abstract

To provide a pen capable of supplying liquid in a pen shaft to a pen tip with a weaker pressing force than that of a conventional squeeze-type pen.SOLUTION: The pen includes a pen shaft 3 which has a liquid storage chamber 2 inside and can be deformed by pressure, and a pen tip 5 which receives a supply of liquid from the liquid storage chamber 2 via a valve body 4. The valve body 4 is housed within the liquid storage chamber 2 and has a flexible tubular member 4a which has one end which can communicate with the pen tip 5 and the other end which is closed, and the tubular member 4a can be flexibly deformed as the pen shaft 3 is pressed and deformed, and has an opening forming portion 4d which opens when flexibly deformed and is closed when not deformed.SELECTED DRAWING: Figure 1

Description

【Technical Field】 【0001】 The present invention relates to pens such as ballpoint pens, felt pens, and makeup pens. More specifically, it relates to a squeeze-type pen configured to accommodate a liquid such as ink in a flexible pen shaft and supply the liquid in the pen shaft to the pen tip by pressing and deforming the pen shaft with a finger. 【Background Art】 【0002】 Conventionally, as this type of pen, there is known a squeeze-type writing instrument in which a liquid is accommodated in a pen shaft and the liquid is sent out to a pen tip attached to the pen shaft by sandwiching and pressing the pen shaft with a finger (Patent Document 1, etc.). 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Utility Model Publication No. 4-36294 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 However, the above-mentioned conventional squeeze-type writing instrument cannot send out the liquid in the pen shaft to the pen tip unless the pen shaft is pressed from both sides with a considerably strong force, and it may be difficult to use for elderly people or the like with weak finger strength. 【0005】 Therefore, the main object of the present invention is to provide a pen that can supply the liquid in the pen shaft to the pen tip with a weaker pressing force than the conventional squeeze-type writing instrument. 【Means for Solving the Problems】 【0006】 To achieve the above objective, the pen according to the present invention comprises a pen shaft having a liquid storage chamber inside and being deformable by pressure, and a pen tip that receives liquid from the liquid storage chamber via a valve body, wherein the valve body is housed in the liquid storage chamber and comprises a flexible cylindrical member having one end that can communicate with the pen tip and the other end closed, wherein the cylindrical member is deformable by bending in accordance with the pressure deformation of the pen shaft and has an opening-forming portion that opens when deformed and closes when not deformed. 【0007】 The cylindrical member comprises a coil spring with closely spaced coils, and the opening can be formed by the spaces between the coils opening up due to the bending deformation of the pen shaft, which causes the coil spring to bend. 【0008】 The pen shaft comprises a rear shaft having the liquid storage chamber inside, and a front shaft that holds the pen tip and is screw-connected to the rear shaft. The cylindrical member may comprise an outer stopper that is connected to one end of the coil spring and has a first liquid passage in its center that communicates with the pen tip, and is fitted into the front end of the rear shaft, an inner stopper that opens and closes the first liquid passage, and a rear end stopper that closes the other end of the coil spring. 【0009】 The outer plug has a connecting portion that is fitted into and connected to one end of the coil spring, and the connecting portion may have threads formed on its outer surface that are screwed into the coil spring. 【0010】 The rear end plug has a fitting portion that is fitted into the other end of the coil spring, and the fitting portion may have threads formed on it that are screwed into the coil spring. 【0011】 The one end of the coil spring has a projection at the tip of the wire constituting the coil spring that protrudes inward in the radial direction of the coil spring, and the projection can be engaged with the outer surface of the outer plug. 【0012】 Depending on the type of pen tip, the coil spring may be configured to have different degrees of flexibility. 【0013】 The cylindrical member includes a rubber tube with one end communicating with the pen tip and the other end closed, and the opening forming portion can be a cut provided on the circumferential surface of the rubber tube. 【0014】 The cut can extend in a direction intersecting the longitudinal direction of the rubber tube. 【0015】 A plurality of cuts can be provided at different positions in the longitudinal direction of the rubber tube. 【0016】 A plurality of cuts can be provided at different positions in the circumferential direction of the rubber tube. 【0017】 The cut can be formed in a spiral shape along the longitudinal direction of the rubber tube. 【Advantages of the Invention】 【0018】 According to the pen of the present invention, the cylindrical member constituting the valve body is elastically deformed as the pen shaft is elastically deformed, and the valve body is opened by the elastic deformation. Therefore, even if the force pressing the pen shaft is smaller than before, the valve body can be opened. 【Brief Description of the Drawings】 【0019】 [Figure 1] It is a central longitudinal sectional view showing an embodiment of the pen according to the present invention. [Figure 2] It is an exploded sectional view of the pen in FIG. 1. [Figure 3] It is an exploded front view of the pen in FIG. 1. [Figure 4] It is a central longitudinal sectional view showing the usage state of the pen in FIG. 1. [Figure 5] It is a plan view showing the valve body incorporated in the pen in FIG. 1. [Figure 6] It is a front view of the valve body in FIG. 5. [Figure 7] It is a sectional view of FIG. 6. [Figure 8] It is a perspective view of the valve body in FIG. 5. [Figure 9]It is a perspective view showing the deflection deformation state of the cylindrical member of the valve body in FIG. 8. [Figure 10] It is a plan view showing a modified aspect of the valve body which is a component of the present invention. [Figure 11] It is a front view of FIG. 10. [Figure 12] It is a cross-sectional view of the valve body in FIG. 10. [Figure 13] It is a perspective view of the valve body in FIG. 10. [Figure 14] It is a plan view showing another modified aspect of the valve body which is a component of the present invention. [Figure 15] It is a perspective view showing the usage state of the pen in FIG. 1. [Figure 16] It is a plan view showing still another modified aspect of the valve body which is a component of the present invention. [Figure 17] It is a perspective view of the valve body in FIG. 16. [Figure 18] It is a cross-sectional view of the valve body in FIG. 16. [Figure 19] It is a cross-sectional view showing the deflection deformation state of the cylindrical member of the valve body in FIG. 16. [Figure 20] It is a perspective view showing still another modified aspect of the valve body which is a component of the present invention. [Figure 21] It is an exploded perspective view of the valve body in FIG. 20. [Figure 22] It is a front view showing the end of the coil spring of the valve body in FIG. 20. 【Embodiments for Carrying Out the Invention】 【0020】 Embodiments of the pen according to the present invention will be described below with reference to FIGS. 1 to 19. Note that throughout all the figures and all the embodiments, the same or similar components are denoted by the same reference numerals. 【0021】 Referring to FIGS. 1 and 2, the pen 1 has a liquid storage chamber 2 inside, a pen shaft 3 that can be elastically deformed by pressing, and a pen tip 5 that receives liquid supply from the liquid storage chamber 2 via a valve body 4. 【0022】 The pen barrel 3 comprises a front barrel 3a and a rear barrel 3b. The front barrel 3a is screw-connected to the rear barrel 3b. The liquid reservoir chamber 2 is formed inside the rear barrel 3b. In this specification, the side with the pen tip is referred to as the front, and the opposite side as the rear. A cap 6 is placed over the front barrel 3a. 【0023】 The pen shaft 3 is made of plastic. The front shaft 3a is rigid, and the rear shaft 3b is flexible. The rear shaft 3b is generally made by blow molding polyethylene resin. In blow molding, the wall thickness can be changed, for example, by changing the inner diameter. Specifically, the part with a larger inner diameter is thinner than the part with a smaller inner diameter. The rear shaft 3b has a shape in which the inner diameter gradually increases from the rear to the front, and has a thin-walled section 3c near the front shaft 3a that is easily deformed by pressure. By attaching a mark such as "PUSH" to this thin-walled section 3c, the pressing area that should be pressed to send the liquid in the liquid storage chamber 2 to the pen tip 5 can be clearly indicated (Figure 3). After deformation by pressure, when the pressing force is released, the rear shaft 3b returns to its original shape due to its retained elasticity. 【0024】 An outer stopper 7 is fitted onto the front end of the rear shaft 3b. The outer stopper 7 has a first liquid passage 7a formed in its center. An inner stopper 8 is inserted into the first liquid passage 7a of the outer stopper 7. The first liquid passage 7a has a small diameter section on its front side, into which the front end of the inner stopper 8 is fitted. When in use, as shown in Figure 4, the inner stopper 8 is pushed from the outside by a means described later, pushing it into the first liquid passage 7a. This causes the front end of the inner stopper 8 to detach from the small diameter section on the front side of the first liquid passage 7a and move to the rear side. The rear side of the first liquid passage 7a has a slightly larger inner diameter than the small diameter section on the front side, creating a small gap between the outer surface of the inner stopper 8 and the inner surface of the rear side of the first liquid passage 7a, allowing liquid to flow through, and opening the first liquid passage 7a. The rear shaft 3b can be provided as a replacement ink cartridge with the inner stopper 8 packed into the outer stopper 7. As will be described later, since the valve body 4 is closed when not deformed, the inner plug 8 can be omitted. 【0025】 Referring to Figures 5 to 9, the valve body 4 includes a flexible cylindrical member 4a. The front end of the cylindrical member 4a is connected to the rear end of the outer stopper 7, and the rear end is closed. The inside of the cylindrical member 4a is in communication with the first liquid passage 7a. 【0026】 The cylindrical member 4a includes a flexible rubber tube 4c, one end of which is connected to the outer stopper 7 by fitting, and the other end which is closed with a rear end stopper 4b. A notch 4d is provided on the circumferential surface of the rubber tube 4c. 【0027】 By pressing the thin-walled portion 3c of the rear shaft 3b, for example, in the direction of arrow X in Figure 4, the cylindrical member 4a is pressed against the inner wall of the rear shaft 3b and elastically deforms by bending, as shown in Figure 9. Due to this bending deformation, the cylindrical member 4a is pulled radially outward and compressed radially inward, causing the notch 4d provided on the radially outward side to open. In this way, the notch 4d forms an opening-forming portion that is closed when not deformed and opens when bending deformation occurs. 【0028】 In the example shown in Figure 5, the notches 4d that constitute the opening extend in a direction intersecting the longitudinal direction of the rubber tube 4c. The notches 4d that constitute the opening can also be provided at an angle to the longitudinal direction of the rubber tube 4c, as shown in Figures 10 to 13, or parallel to the longitudinal direction of the rubber tube 4c, as shown in Figure 14. It is preferable to provide multiple notches 4d at different positions along the axial direction of the rubber tube 4c. In order to use up as much of the liquid in the storage chamber 2 as possible, it is preferable to also provide notches 4d near the base of the rubber tube 4c. Furthermore, it is preferable to provide multiple notches 4d at different positions along the circumferential direction of the rubber tube 4c so that the opening can be created even when different positions around the thin-walled portion 3c are pressed. The notches 4d can also be formed in a spiral shape along the longitudinal direction of the rubber tube 4c. 【0029】 When the rear shaft 3b is pressed, the inside of the liquid storage chamber 2 is pressurized, so the liquid inside the liquid storage chamber 2, for example, black ink, enters the cylindrical member 4a through the open notch 4d and is supplied to the pen tip 5 through the first liquid passage 7a of the outer stopper 7. 【0030】 The rear shaft 3b can be pressed by, for example, as shown in Figure 15, placing the tip of the middle finger on the front shaft 3a and the base of the index finger on the rear shaft 3b, and pressing the thin-walled portion 3c of the pen shaft 3 with the thumb between them, thereby deforming the thin-walled portion 3c of the rear shaft 3b. By doing so, the rear shaft 3b can be deformed with less force than by pinching and pressing the rear shaft 3b from both sides with the fingertips of two fingers, and the cylindrical member 4a can be bent and deformed. 【0031】 The cylindrical member 4a extends in the longitudinal direction of the pen shaft 3. The length of the cylindrical member 4a should be such that when the thin-walled portion 3c is pressed, the cylindrical member 4a flexes and deforms, causing the notch 4d that forms the opening to open. Therefore, the length of the cylindrical member 4a should be within the range of the thin-walled portion 3c that presses against the rear shaft 3b. The length of the cylindrical member 4a can be half the length of the rear shaft 3b or less, and preferably one-third the length of the rear shaft 3b or less. For example, the length of the cylindrical member 4a can be 2.5 cm to 5 cm. By shortening the cylindrical member 4a, the volume of the liquid storage chamber 2 that can hold liquid is increased, and sufficient space can be secured to house the stirring ball in the liquid storage chamber 2 when storing liquid that requires stirring. 【0032】 In this embodiment, the pen tip 5 is exemplified as the tip of a brush pen having the tip of a calligraphy brush. The pen tip 5 may also be the tip of a felt-tip pen, a makeup pen, or the like. 【0033】 The pen tip 5 is held in the holder 9, with its tip protruding from the holder 9 (Figures 1 to 3). A stopper with a projection 10 is provided at the rear of the holder 9, which has a second liquid passage 10a that communicates with the first liquid passage 7a of the outer stopper 7. The holder 9 and the stopper with projection 10 are housed and held within the front barrel 3a. After removing the front barrel 3a from the rear barrel 3b and removing the spacer collar 11 that was sandwiched between the front barrel 3a and the rear barrel 3b, the male threaded portion 3b1 of the rear barrel 3b is screwed back into the female threaded portion 3a1 of the front barrel 3a. As shown in Figure 4, the projection 10b of the stopper with projection 10 pushes the stopper 8 into the first liquid passage 7a, opening the first liquid passage 7a. 【0034】 Figures 16 to 19 show modified versions of the cylindrical member. The modified cylindrical member 4e includes a coil spring 4f with closely spaced coils. The other configurations are the same as those of the pen with the rubber tube described above, so a detailed explanation is omitted. 【0035】 The coil spring 4f is a tension coil spring (a tension coil spring without hooks at both ends) in which adjacent coils are tightly packed together without any gaps. One end of the coil spring 4f is fitted into the outer stopper 7 and connected, and the other end is closed by the rear end stopper 4g. As shown in Figure 18, when the coil spring 4f is not deformed, the coils are tightly packed together and closed, and as shown in Figure 19, when it is deformed, the space between the coils 4h opens up, forming an opening-forming section. 【0036】 By constructing the cylindrical member 4e with a coil spring 4f, the opening formed between the coils of the coil spring 4f is formed over a predetermined range along the entire length of the cylindrical member 4e. Therefore, within this predetermined range, the opening can be opened regardless of the position where the thin-walled portion 3c of the pen shaft 3 is pressed, by pressing any point on the thin-walled portion 3c. 【0037】 Figures 20 and 21 show yet another embodiment of the cylindrical member. The cylindrical member 4e shown in Figures 20 and 21 differs in the shape of the outer plug 7 and rear plug 4g from those shown in Figures 16 to 19. 【0038】 Referring to Figures 20 and 21, the coil spring 4f is fitted onto the connection portion 7b of the outer plug 7. Therefore, the connection portion 7b of the outer plug 7 shown in Figures 20 and 21 is formed by a cylindrical small-diameter portion having an outer diameter that fits inside the coil spring 4f. The rear end plug 4g is also attached to the coil spring 4f by having a small-diameter cylindrical fitting portion 4g1 fitted onto the coil spring 4f. 【0039】 As shown in Figure 21, the connecting portion 7b has threads 7b1 formed on its outer surface, and these threads 7b1 are screwed into the coil spring 4f. This screw-in connection prevents the coil spring 4f from coming off the outer stopper 7 even when the coil spring 4f is repeatedly deflected by using a pen, as shown by the dashed line in Figure 20. Furthermore, the screw-in connection eliminates the need to use adhesive to connect the coil spring 4f and the outer stopper 7, making the connection simpler. Threads 4g2 are also formed on the outer surface of the fitting portion 4g1 of the rear end stopper 4g, and these threads 4g2 are screwed into the rear end of the coil spring 4f. 【0040】 Referring to Figure 22, in the manufacturing process of the coil spring 4f, after the steel wire is wound into a coil, a projection 4f1 is formed by burrs generated when it is cut with a cutting tool. The projection 4f1 protrudes inward in the radial direction of the coil spring 4f from the tip of one end of the wire material that makes up the coil spring 4f. Therefore, the projection 4f1 catches on the outer surface of the outer plug 7 and locks in place. This makes it possible to more effectively prevent the coil spring 4f from coming off the outer plug 7. 【0041】 The coil spring 4f is not limited to metal such as stainless steel or spring steel; it may also be made of resin. A resin coil spring 4f is easier to recycle because there is no need to separate the metal and resin parts when disposing of a used pen. 【0042】 Depending on the type of pen tip, it is desirable to be able to change the amount of liquid supplied from the liquid reservoir 2 (Figure 1) to the pen tip 5 (Figure 1). For example, a thicker pen tip requires a larger amount of liquid to be supplied than a thinner pen tip. Also, a pen tip made of a material that allows ink to pass through easily requires a larger amount of ink to be supplied than a pen tip made of a material that does not allow ink to pass through easily. The degree to which the coil spring 4f can be bent can be changed by changing the wire diameter of the wire material that makes up the coil spring 4f. Alternatively, the degree to which the coil spring 4f can be bent can also be changed by changing the setting of the initial tension of the coil spring 4f during the manufacturing process. Compared to a coil spring 4f with a low degree of flexibility, a coil spring 4f with a high degree of flexibility will bend more when bent with the same force, and the gap between the coils will be larger, so the amount of liquid supplied from the liquid reservoir 2 to the pen tip 5 will be increased. Therefore, depending on the type of pen tip, such as its thickness and material, different coil springs 4f with varying degrees of flexibility may be used. 【0043】 In all of the embodiments described above, the cylindrical members 4a and 4e can be made shorter than, for example, the pipes (inner pipe 4, outer pipe 5) in the prior art (Japanese Utility Model Publication No. 4-36294), thus shortening the path for supplying the liquid such as ink from the liquid storage chamber 2 to the pen tip 5. As a result, the generation of air bubbles (bubble clogging) in the liquid (ink, etc.) when it is dispensed to the pen tip 5 is reduced. This reduces the likelihood of bubbles bursting at the pen tip 5 and staining the artwork. 【0044】 The present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. For example, in the above embodiments, a pen shaft 3 in which the front shaft 3a and the rear shaft 3b are screw-connected is illustrated, but a pen shaft in which the front shaft and the rear shaft are integrally molded is also possible. [Explanation of symbols] 【0045】 1 pen 2 Liquid storage chamber 3 Pen shaft 4 Valve body 4a Cylindrical member 4c rubber tube 4d cut (opening formation section) 4e Cylindrical member 4f coil spring 4h Between coils (opening formation section) 5 nibs

Claims

[Claim 1] A plastic pen barrel having a rigid front barrel and a flexible rear barrel with an internal liquid storage chamber that can be deformed by pressure, The pen tip is held on the front shaft and receives liquid from the liquid storage chamber via a valve, The valve body is housed in the liquid storage chamber and comprises a flexible cylindrical member having one end that can communicate with the pen tip and the other end that is closed. The cylindrical member is connected to the front end of the rear shaft at only one end and is capable of bending and deforming in accordance with the pressing deformation of the rear shaft, and has an opening-forming portion on its circumferential surface that opens when it bends and closes when it is not deformed. pen. [Claim 2] The cylindrical member comprises a coil spring with coils closely spaced together. The pen according to claim 1, wherein the opening is formed by the space between the coils that opens when the coil spring bends due to the bending deformation of the rear shaft. [Claim 3] The pen according to claim 2, comprising a first liquid passage in the center that communicates with the pen tip, a stopper for opening and closing the first liquid passage inserted into the center, and one end of the coil spring connected to an outer stopper fitted into the front end of the rear shaft, with the other end of the coil spring closed by a rear end stopper. [Claim 4] The outer plug has a connecting portion that is fitted into and connected to one end of the coil spring, The pen according to claim 3, wherein the connecting portion has threads formed on its outer surface that are screwed into the coil spring. [Claim 5] The rear end plug has a fitting portion that is fitted into the other end of the coil spring, The aforementioned fitting portion has threads formed on its outer surface that are screwed into the coil spring. The pen according to claim 3. [Claim 6] The one end of the coil spring has a projection at the tip of the wire constituting the coil spring that protrudes inward in the radial direction of the coil spring. The projection engages with the outer surface of the outer plug. The pen according to claim 4. [Claim 7] The pen according to claim 2, wherein the ease with which the coil spring flexes differs depending on the type of pen tip. [Claim 8] The cylindrical member comprises a rubber tube with one end communicating with the pen tip and the other end closed. The pen according to claim 1, wherein the opening forming portion is a notch provided on the circumferential surface of the rubber tube. [Claim 9] The pen according to claim 8, wherein the notch extends in a direction intersecting the longitudinal direction of the rubber tube. [Claim 10] The pen according to claim 9, wherein the aforementioned notches are provided in multiple locations at different positions along the longitudinal direction of the rubber tube. [Claim 11] The pen according to claim 8, wherein the aforementioned notches are provided in multiple locations at different positions in the circumferential direction of the rubber tube. [Claim 12] The pen according to claim 8, wherein the notch is formed spirally along the longitudinal direction of the rubber tube. [Claim 13] The pen according to claim 8, comprising a first liquid passage in the center that communicates with the pen tip, a stopper for opening and closing the first liquid passage inserted into the center, and one end of the rubber tube connected to an outer stopper fitted into the front end of the rear shaft, with the other end of the rubber tube closed by a rear end stopper.

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