Writing instrument with finger gripping device

[0002] This is a continuation of application Ser. No. 09/048,280, filed Mar. 26, 1998, now U.S. Pat. No. 6,164,855.

[0003] The present invention relates generally to writing instruments such as ink pens, pencils, felt tip markers and the like. More specifically, this invention relates to a writing instrument having a gripping device thereon.

[0004] Handwriting remains an important and useful skill and manual writing instruments remain important tools. Most writing instruments include an elongated tube containing a writing medium, such as ink or pencil lead, or highlighting medium, such as yellow, green and pink highlighters or the likes, and having an end at which the writing or highlighting medium is exposed for contact with the writing surface, such as paper. The elongated tube section of the writing instrument, which is grasped and held by the user when writing, is characterized typically by a smooth, exterior surface. The smooth surface may be attractive and pleasant to the touch, but it can be become slippery during use resulting in writer discomfort and impaired legibility of the handwritten text produced.

[0005] Devices are known in the prior art to assist a user in manually gripping a writing instrument. U.S. Pat. No. 4,601,598 to Schwartz et al., U.S. Pat. No. 5,468,083 to Chesar, U.S. Pat. No. 4,167,347 to Hoyle, and U.S. Pat. No. 4,932,800 to Lin et al. illustrate pen or pencil attachment devices which may be attached to the writing instrument in an attempt to reduce writer discomfort, cramp and fatigue. These writing aids are typically structures designed to fit over the exterior of a writing instrument. These independent structures which are slid onto the exterior of the instrument tend to be bulky and thick, and create a non-uniform surface constraining the user to hold the writing instrument in a fixed position.

[0006] Other structures have contoured grip surfaces constituting complex molded surfaces aimed at approximating the anatomical contours of a writer's fingertips during grasping of the writing instrument. However, the grip surfaces are not able to match the differing anatomical shapes and pen grasping techniques of different individuals.

[0007] U.S. Pat. No. 5,221,152 to Chuang discloses a writing instrument having a gripping segment on a section of the pen, which screws onto a portion of a main body of the writing instrument. The gripping segment comprises a number of annular slip-preventing grooves axially disposed on its outer peripheral surface to help retain the instrument to the material or surface it is clipped to. It is not concerned with providing comfort and ease to the user of the instrument when writing.

[0008] U.S. Pat. No. 5,000,599 to McCall et al. discloses a writing instrument having a deformable gripping portion, which deforms in response to manual pressure during manual grasping of the instrument to permit reshaping of the gripping portion from an initial shape to a custom fit shape generally conforming to the writer's fingertips. The gripping portion retains the custom fit shape for a short period after release and returns substantially to its initial shape. During operation, the gripping portion requires pressure to be applied at the onset to conform the gripping portion to the shape desired by the user.

[0009] Thus, there remains a need to provide a gripping surface for a writing instrument which is consistent and uniform with the surface of the writing instrument, is comfortable and easy to use, provides a firm grip and does not require excessive pressure to conform the shape desired by the user.

[0010] These objects and advantages as well as other objects and advantages are accomplished in a writing instrument including an elongated cylindrical body preferably in the form of a cartridge element carrying a writing or highlighting medium therein and having a writing tip exposed at one end. The cartridge element is insertable into a barrel member and may be permanently bonded to the barrel or releasably attached so that a replacement cartridge may be inserted into the barrel member when the writing or highlighting medium therein is depleted.

[0011] In a preferred embodiment of the invention the cartridge element includes a reduced cross-section thereon which forms an annular recessed tapered cavity. A gripping member is received by the cavity. The gripping member is preferably tubular in shape and is tapered to follow the tapered contour of the cartridge element. Gripping member may be permanently attached to the annular recessed cavity by means of co-extrusion, two-component injection molding, or by chemical or mechanical bonding.

[0012] The gripping member has a smooth surface which may include a slightly elevated or raised pattern thereon. Preferably, the elevated pattern may be constructed in the form of hexagons having sides which are contiguous with neighboring hexagonal sections and are interconnected so as to form a continuous lattice or pattern of hexagons on the smooth surface. The pattern is preferably continuous over the entire smooth surface. Moreover, the pattern may be formed from shapes which are not connected, but which are disposed throughout the smooth surface.

[0013] The elevated pattern formed on the smooth surface provides friction between the gripping section and a user's fingers, and is resiliently compressible by the user's fingers for an improved grip. When in use, the writing instrument is grasped by a user at the gripping section. The gripping section provides a soft, textured and compressible surface which is comfortable to the touch and is not prone to slippage between the user's thumb and fingers. Since the gripping surface is permanently attached to the body of the pen, the possibility of having the gripping member becoming loose during use is greatly reduced. In another aspect of the invention, a cap may be provided on the cartridge element and fitted over the gripping member and the writing tip to cover same.

[0014] Features of the present invention are disclosed in the accompanying drawings, wherein similar reference characters denote similar elements throughout the several views, and wherein:

[0015] FIG. 1 is a front view of the writing instrument of the present invention showing the gripping section thereon;

[0016] FIG. 2 is a partial sectional view of the writing instrument shown in FIG. 1 illustrating the features of the gripping section;

[0017] FIG. 3 is a sectional view of the writing instrument of FIG. 1 shown with a cap member thereon;

[0018] FIG. 4 is a front view of the writing instrument shown in FIG. 1 with the cap member;

[0019] FIG. 5 is a cross-sectional view of the cap member; and

[0020] FIG. 6 is a top view of the cap member.

[0021] FIG. 7 is a block diagram schematically showing a method of co-injection or two-component or two-step injection molding a writing instrument with a gripping member; and

[0022] Turning to FIGS. 1 through 3, an embodiment of a writing instrument 10 constructed in accordance with the present invention is shown with the understanding that those of ordinary skill in the art will recognize many modifications and substitutions which may be made to various elements.

[0023] Writing instrument 10 generally includes an elongated cylindrical body 12 preferably in the form of a cartridge element carrying a writing or highlighting medium therein and having a writing tip 14 exposed at a tip opeining 42 at one end of the cartridge element. Elongated body 12 of FIG. 2 is hollow and tubular in shape and has an axial bore extending longitudinally therethrough. Cartridge element 12 is insertable into a barrel member 13 and may be permanently bonded thereto or releasably attached so that a replacement may be inserted into barrel member 13 when the writing highlighting medium therein is depleted. Methods of attachment include but not limited to press fitting, snap fitting, chemical bonding and ultrasonic bonding. Additionally, it is preferred that cartridge element 12 comprises threads 21, as shown in FIG. 2, configured and dimensioned to be received by corresponding internal threads 22 defined on the inside of barrel 13, as shown in FIG. 3, so that barrel 13 and cartridge element 12 can be releasably attached to each other. Writing instrument 10 may also include a writing or highlighting medium that is retractable with respect to cartridge element 12, so that the writing or highlighting medium may be selectively positioned outside cartridge 12 when writing is desired and be retracted into cartridge 12 for storage and transport.

[0024] In a preferred embodiment of the invention and as depicted in FIG. 1, cartridge element 12 includes a reduced cross-section, which forms an annular recessed tapered cavity 15. The recessed cavity 15 has a first end wall 46 adjacent writing tip 14 and a second end wall 48 axially spaced therefrom. Gripping member 16 has a first end 50 and a second end 52 positioned between the first end wall 46 and second end wall 48 of recessed cavity 15. Gripping member 16 is positioned on elongated body 12 adjacent tip opening 42, and in FIG. 2 is received in cavity 15 and flush with a stepped member 17 on body 12 adjacent first end wall 46. As shown stepped member 17 has a diameter that is slightly less than the diameter of raised section 19 of body 12 adjacent second end wall 48, such that raised section 19 can facilitate the insertion of a cap member, as discussed below. Preferably, gripping member 16 is suitably dimensioned and shaped to fit smoothly within recess 15 of cartridge element 12. Gripping member 16 is also preferably tubular in shape and is tapered to follow the tapered contour of cartridge element 12. Preferably, gripping member 16 is fabricated of a thermoplastic elastomer, including but not limited to polypropylene, rubber, polyurethane, polyisobutylene, polybutadiene. Moreover, in order to provide comfort and ease during operation of the writing instrument, it is important that gripping member 16 be of a suitable softness. The gripping member is preferably fabricated of a material which is softer than the material of the writing instrument body. Preferably, the hardness of the material of gripping member 16 is in the range of Shore A hardness of 3 to 40 durometer, and more preferably in the range of 3 to 25 durometer, and most preferably in the range of 3 to 15 durometers. However, the gripping member may also have a hardness of less than 3 durometer.

[0025] Gripping member 16 is adhered to cartridge element 12 by kinetic, ultrasonic or laser welding. Alternative methods of adhering gripping member 16 to cartridge element 12 include but are not limited to solvent bonding and co-injection molding. The gripping member and the cartridge element may also be manufactured by a two-component injection molding process, which produces a chemical bond between these two members. A co-injection or two-component or two-step injection molding process is schematically illustrated in FIG. 7.

[0026] Gripping member 16 has a smooth surface 18 which may include a slightly elevated or raised pattern thereon. Preferably, the pattern comprises a plurality of slightly elevated sections 20, the pattern may extend over an entire peripheral portion of the smooth outer surface. In the illustrated embodiment of FIG. 1, the elevated sections 20 comprise interconnected polygons. As shown in FIG. 1, elevated sections 20 are in the form of hexagons having sides which are contiguous with neighboring hexagonal sections and interconnected so as to form a continuous lattice or pattern of hexagons on smooth surface 18. The pattern is preferably continuous over the entire smooth surface 18. The elevated pattern 20, which preferably has less surface area than the smooth surface 18, is resiliently deformable by the user's fingers, so that additional traction between the gripping member and the user's fingers is provided in addition to the friction between the gripping member and the user's fingers. Moreover, the pattern may be formed of shapes which are not connected, but which are disposed continuously throughout smooth surface 18.

[0027] When in use, the writing instrument is grasped by a user at the gripping section. The gripping section provides a soft, textured surface which is resiliently deformable and is therefore not prone to slippage between the user's thumb and fingers. Since the gripping surface is permanently attached to the body of the pen the possibility of having the gripping member becoming loose during use is greatly reduced. The thickness of gripping member 16 is preferably in the range of 0.50 to 2.0 mm as measured from smooth surface 18 to elevated sections 20. The elevated pattern 20 is preferably the range of 0.1 to 0.5 mm as measured from smooth surface 18.

[0028] As shown in FIG. 3, another aspect of the invention includes a cap 24 provided on cartridge element 12, which is dimensioned to fit over at least a portion of gripping member 16 and writing tip 14 to cover same. Preferably, cap 24 cooperates with raised section 19 to ensure a tight connection between cap 24 and cartridge 12. Gripping member 16 is of sufficient size, shape and thickness to provide a comfortable, flexible surface having anti-slip properties. It is not bulky to grip, is able to fit neatly on cartridge 12 and can be easily covered by cap 22.

[0029] Referring to FIGS. 4-6, writing instrument 10 is shown with cap member 24. Cap 24 is configured and dimensioned to be releasably attached to cartridge element 12. Cap 24 protects writing tip 14 when the writing instrument 10 is not in use, and it also isolates the ink from writing tip 14 from contaminating the surrounding areas. Cap 24 comprises a hollow body 26 defining an open end, clip member 28, vented plug 30 and well 32. When not in used writing tip 14 is inserted into well 32, which is preferably attached to vented plug 30 by snap fitting, threading, chemical bonding or ultrasonic bonding. Well 32 can also be formed integrally with vented plug 30. Plug 30 defines a plurality of apertures 34 therein such that air communication is established the interior of cap 24 and the outside environment through plug 30.

[0030] The writing instrument of the present invention may be manufactured by providing a cartridge element having a writing or highlighting medium therein and a writing tip thereon. A tubular shaped gripping member is provided and is adhered to the cartridge element by a two-step injection molding process to chemically bond the gripping member to the cartridge element. Alternatively, the gripping member may be mechanically bonded to the cartridge element by laser or ultrasonically welding or solvent bonding the member to the cartridge element.

[0031] While various descriptions of the present invention are described above, it should be understood that the various features can be used singly or in any combination thereof. Therefore, this invention is not to be limited to only the specifically preferred embodiments depicted herein.

[0032] Further, it should be understood that variations and modifications within the spirit and scope of the invention may occur to those skilled in the art to which the invention pertains. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is accordingly defined as set forth in the appended claims.