Patent Application
20120315074
The present invention relates generally to the field of writing instruments and in particular to a new and useful writing instrument configured with multiple independently selectable marking tips.
Multi-function writing instruments provide the user with multiple writing tip options within the same writing implement, which reduces the number of writing instruments to carry.
Typical multi-function writing instruments include both ink-based and lead pencil tips. Maximum use of the lead pencil tip can be achieved through use of an eraser which is typically fixed to the writing instrument. Since the eraser will only be used in connection with the lead pencil tip, the eraser is typically either covered while not in use or always exposed.
An example of the former method is the use of screw-top eraser covers on multi-function instruments. These screw-on covers require an extra step in the use of the writing instrument, reducing the enjoyment and utility of their use. Further, the cover is a separate part that is liable to be lost and negatively impacts the aesthetics and style of the writing instrument.
In the past, there have been proposed writing instruments having only a single writing cartridge in which a writing tip and an eraser are simultaneously projected or retracted from opposite open ends of the writing instrument. Such a writing instrument is disclosed in, for example, U.S. Pat. No. 4,221,490 to Malm. Other proposed writing instruments have multiple cartridges and an eraser which is projected independently without any coordination with the projection of the writing tip. Such a writing instrument is disclosed in, for example, U.S. Pat. No. 5,890,825 to Kageyama.
The constructions of these prior writing instruments, however, are complicated and fail to provide a projection and retraction mechanism for simultaneously projecting and retracting a lead pencil tip and an eraser in a multi-function writing instrument.
It is an object of the present invention to provide a multi-function writing instrument with an automatic projecting eraser, which only projects when the lead pencil tip is selected for use. Thus, this writing instrument matches the eraser's availability to the user's demand.
It is a further object of the invention to provide a multi-function writing instrument with a relatively simple and inexpensive project and retract mechanism capable of simultaneously projecting or retracting a lead pencil tip and an eraser from opposite ends of a multi-function writing instrument.
For achieving the aforementioned objects, according to the present invention, there is provided a multi-function writing instrument of the invention having two complimentary bodies, such as an upper barrel and a lower barrel, which are joined to form a single writing instrument for use as a mechanical pencil and a ballpoint pen, non-marking stylus, fountain pen, rolling ball or felt-tip marker, or any other type of marking instrument. The lower barrel has a chamber for holding the mechanical pencil element, including the lead pencil, and one or more ink cartridges or other types of marking implements, e.g., stylus. The writing tips of the lead pencil and the ink cartridges are extendable one at a time through an opening in the lower barrel writing tip.
The non-writing tip end of the lower barrel is open and forms a sleeve for rotatably connecting to the upper barrel. The upper barrel has an eraser opening at its free end opposite the writing tip opening. An eraser holder for supporting an eraser is movably housed in the upper barrel. The eraser holder has an eraser follower in the form of a protuberance on the surface of the eraser holder. The eraser holder preferably includes a mounting part for holding the eraser and a stem. An eraser holder spring which is mounted in the upper barrel urges the eraser holder away from the eraser opening.
A means for propelling simultaneously the pencil lead marking tip through the writing point opening and the eraser through the eraser opening in the upper barrel is housed in the barrel of the writing instrument. The means for propelling includes a guide connected to the lower barrel. The guide has a first guide end and a second guide end. The guide also includes a plurality of channels which are aligned with a center axis of the guide and extend between the first guide end and the second guide end.
A cam follower is slidably mounted in each of the channels. The cam follower is connected to a refill holder or a lead pencil holder, such as a mechanical pencil implement, which are stored in the barrel of the writing instrument. Each cam follower is operatively connected to a writing or marking tip. A means for biasing urges each cam follower toward the eraser opening in the upper barrel. The biasing means preferably comprises a helical spring which is coiled around the refill holder and abuts inner wall of the first guide end and the cam follower.
A first cam is rotatably connected to the guide. The first cam includes a first cam path having a first cam apex. The cam followers travel on the first cam path upon rotation of the first cam relative to the guide. The first cam apex urges the cam follower against the force of the cam follower spring toward the writing point opening. The writing tip which is connected to the cam follower that is being urged by the first cam apex passes through the writing point opening to the use position. The first cam imparts a translational movement to the cam follower, which, in turn, causes the writing tip to linearly move parallel the longitudinal axis of the writing instrument.
A second cam is also rotatably connected to the guide. The second cam includes a second cam path having a second cam apex. The eraser follower travels on the second cam path upon rotation of the second cam relative to the guide. The second cam apex urges the eraser follower to move toward the eraser opening against the force of the eraser holder spring. The eraser holder undergoes a translational displacement which, in turn, causes the eraser to pass through the eraser opening.
The eraser projects through the eraser opening upon selection of the lead pencil. The lead pencil is selected upon rotation of the upper barrel relative to the lower barrel. The eraser projects through the eraser opening simultaneously when the pencil lead tip projects through the writing tip opening.
To operate the multi-function writing instrument, the upper barrel is turned relative to the lower barrel. The rotation propels and repels individually in succession the writing tips of the ink refill and the lead pencil. Upon propelling the lead pencil tip, the eraser projects through the opening of the upper barrel. Thus, the eraser is available for use only when the pencil writing tip is projected, which is the only time the user would need to use the eraser.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
In the drawings:
Referring now to the drawings, in which like reference numerals are used to refer to the same or similar elements,
Referring to
A barrel insert 21 is coaxially disposed inside and fixed to the lower barrel 20 against relative rotation. The barrel insert 21 connects the guide 50 to the lower barrel 20. The barrel insert 21 has a hollow cylindrical body 22, a neck 23, a stem 24, a top opening 26 and a bottom opening 25. The neck 23 has a larger inner diameter than the stem 24. The guide 50 is received in the top opening 26 and neck 23 of the barrel insert 21. Inwardly facing protuberances (not shown) on the inside of the barrel insert 21 fix the guide 50 inside the barrel insert 21. The lower barrel 20, the guide 50 and the barrel insert 21 are fixed against relative movement.
Referring to
The drum 56 has an opening 59 opposite the second inner wall 53b. Referring to
A plurality of channels 55 are formed in the main body 51 of the guide 50 between the first inner wall 53a and the second inner wall 53b. Each channel 55 has a top opening defined by edge 55a on the exterior surface of the main body 51. The channels 55 are circumferentially spaced equally from each other around the longitudinal axis of the main body 51. Each channel 55 is aligned with an opening 54 of the first inner wall 53a.
The base 52 of the guide 50 is disposed in the neck 23 of the barrel insert 21. A plurality of grooves 57 are formed on the inner surface of the base 52. Each groove 57 is aligned with an opening 54 of the first inner wall 53a.
The guide 50 may comprise a single molded piece formed of a plastic material.
A lead pencil holder 4 (see
Referring to
The lead pencil cam follower 60 is connected to the lead pencil holder 4. Both the lead pencil cam follower 60 and the channel 55 in which the cam follower 60 is slidably disposed are aligned with the projection 58 of guide 50. The projection 58 is preferably located proximate the top end of the channel 55 which receives the lead pencil cam follower 60. Each of the other cam followers 60 is connected to a refill holder 5.
The raised profile 62 of the cam follower 60 extends out of the opening of the channel 55 above the edge 55a.
Referring to
Referring to
The backward facing cam 32 extends from the top edge 38 of the curved wall 37. The backward facing cam 32 includes a slanted edge 32a, a vertical straight edge 32b which is perpendicular to the top edge 38, and an apex 32c located between the slanted edge 32a and the vertical straight edge 32b, which all define a path adapted for travel by an eraser holder follower 44.
The forward facing cam 33 is disposed inside the hollow body 31. The forward facing cam 33 is preferably integral with the inner surface of the hollow body. The forward facing cam 33 can also be a separate member that is disposed in the hollow body 31.
The forward facing cam 33 includes connected paths adapted for travel of the cam followers 60. The connected paths include a first sloped path 33a, a second shorter sloped path 33b, a short vertical path 33c that extends from the second sloped path 33b, an apex 33d that connects the first sloped path 33a and the short vertical path 33c and a circumferential path 36e that is connected to the first sloped path 33a and the second shorter sloped path 33b. The circumferential path 36e includes a plurality of recesses 33f, preferably three (3). A ridge 33g separates each recess 33f.
The pitch, length and direction of the first cam's path is different from the pitch, length and direction of the second cam's path to allow for different translational displacements of the eraser and writing tip.
The apex of the backward facing cam and/or the apex of the forward facing cam preferably have a flat, straight edge. The apex of the backward facing cam and/or the apex of the forward facing cam also preferably have a curved profile with an angle of rotation of 5 degrees to 45 degrees, more preferably from 5 degrees to 36 degrees, and most preferably from 5 degrees to 24 degrees.
The cam assembly 30 is rotatably mounted to and axially slidable in the guide 50. The projection 58 of the guide 50 is shaped and sized to slidably engage the slot 34a in the top opening 34 of the cam assembly 30. The cam assembly 30 is not rotatable relative to the guide 50 when the projection 58 is engaged with the slot 34a. The engagement of the projection 58 and the slot 34a allows the cam assembly 30 and thus, the upper barrel 10, to axially slide forward for knocking the lead pencil holder 5 to advance the lead pencil 2 through the writing tip opening 27.
A ring 46, shown in
The slot 34a formed in the top opening 34 of the cam assembly 30 is aligned with and on the same plane as the apex 33d of the forward facing cam 33. The slot 34a is also diametrically aligned with the apex 32c of the backward facing cam 32.
Referring to
Referring to
The eraser 43 is axially displaced from a retracted position, where it is housed inside the upper barrel insert 12, to an extended position, where it extends through the eraser opening 11 for use. The eraser holder 40 has an eraser follower 44 disposed on the exterior surface proximate the top end of the eraser holder 40. The eraser follower 44 travels on the path of the backward facing cam 32 upon rotation of the guide 50 relative to the cam assembly 30 for propelling the eraser 43 from its retracted position to its extended position. The propulsion of the eraser 43 is simultaneous or substantially simultaneous with the propulsion of the lead pencil tip through the writing tip opening 27 of the lower barrel 20.
An eraser spring 45, shown in
The guide 50 is fixed to the lower barrel 20. The cam assembly 30, in turn, is fixed to the upper barrel 10. Rotation of the lower barrel 20 relative to the upper barrel 10 causes actuation of the writing instrument by rotating the guide 50 relative to the cam assembly 30. The cam assembly 30 urges the cam followers 60 to travel in the guide channels 55 toward the writing tip opening 27 of the lower barrel 20 to propel a writing tip. Rotation of the lower barrel 20 relative to the upper barrel 10 is continued until the desired refill 2,3 is propelled.
The step 63 of the cam follower 60 travels on the path of the forward facing cam 33 upon rotating the lower barrel 20 relative to the upper barrel 10. The step 63 sits in the recess 33f when the writing tip of the refill 2,3 is inside the lower barrel 20. Upon rotating the lower barrel 20 relative to the upper barrel 10, the step 63 travels on the recesses 33f. Upon further rotation, the step 63 climbs the first slope 33a until it reaches and abuts against the apex 33d. The apex 33d pushes the cam follower 60 against the force of the guide spring 70 housed in the channel of the guide 50. The writing tip passes through the writing tip opening 27 of the lower barrel 20 when the step 63 of the cam follower 30 abuts against the apex 33d of the forward facing cam 33. Continual rotation of the lower barrel 20 relative to the upper barrel 10 causes the step 63 of the cam assembly 30 to travel off of the apex 33d and onto the straight path 33c, the second slope 33b and return to the recesses 33f.
The relative rotation of the cam assembly 30 and the guide 50 also actuates the projection of the eraser 43 through the top opening of the upper barrel assembly 10. The eraser holder follower 44 sits on the top edge 38 of the of the cam assembly 30 when the eraser 43 is in the retracted position. Rotation of the cam assembly 30 causes the eraser holder follower 44 to travel on the backward facing cam 32, which, in turn, causes the eraser holder 40 to move axially against the force of the eraser spring 45. When the eraser holder follower 44 reaches the apex 32c of the backward facing cam 32, the eraser holder 40 is at its highest point and the eraser 43 is in the extended position.
The location of the lead pencil refill 4 and its cam follower 33 relative to the forward facing cam 33 and the backward facing cam 32, and the relation between the forward facing cam 33 and the backward facing cam 32 allow for simultaneous axial movement of the eraser 43 to the extended position and the lead pencil 2 to the writing position.
The apex 32c of the backward facing cam 32 and the apex 33d of the forward facing cam 33 lie on parallel longitudinal planes. The apex 33d is also aligned with the slot 34a in the top opening 34 of the cam assembly 30. The channel 55 which slidably receives the lead holder 4 and its connected cam follower 33 is aligned with the projection 58 of the guide 50. Thus, the apex 32c urges the eraser holder follower 44 at approximately the same time when the apex 33d urges the step 63 of the cam follower 33 for the lead refill 4.
The projection 58 of the guide 50 is received in the slot 34a of the cam assembly 30 when the eraser 43 is propelled to its extended position. The engagement of the projection 58 and slot 34a allows for knocking of the eraser to forward lead 2 from the lead refill 4.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
