Patent Application
20200094611
This disclosure generally relates to writing instruments, and more specifically relates to side-knock mechanisms for use with mechanical pencils.
Writing instruments, and specifically pencils, have been in widespread use for hundreds of years, with mechanical pencils dating as far back as the 18th century. With the advent of mechanical pencils, a pencil could be used continuously by simply refilling the modular lead housed in the body. A variety of different mechanical pencil configurations are known in the art including various mechanisms for retaining and advancing lead or other writing mediums within the writing instrument. In general, mechanical pencils expose the lead for writing by driving it forward when a knock button is pressed. The knock button may be disposed on the end of the pencil, or on the side. Generally at rest, the lead is selectively fixed by a split chuck or similar gripping mechanism that cooperates with the lead tube to hold the lead and deliver it to the writing tip of the writing instrument. Upon the actuation of the knock button, the mechanism cycles, a process which includes advancing the lead tube, which increases the force exerted by a return element on the lead tube, which opens the chuck, and allows the lead tube to walk back with respect to the lead without moving the lead.
In conventional side-knock configurations, any slight rotation of the lead tube with respect to the knock button must be prevented during actuation in order to ensure that the knock button properly aligns with the feature on the lead tube to completely cycle the mechanism. Rotation of the lead tube in such a conventional side-knock style writing instrument can cause undesirable misalignment of the knock button and the lead tube feature that can result in failure of the mechanism to cycle, meaning failure of the tube to advance, or result in reduced actuation distance that impairs lead delivery to the writing tip of the instrument.
Conventional side-knock writing instruments typically include a guide structure either on the barrel, the lead tube, or both, to prevent such rotation. Guides can include grooves on the barrel or cooperating structures between the lead tube and the barrel that prevent rotation during actuation. This adds complexity and cost to the manufacture of the writing instruments. Such additional structures must be aligned during assembly of the writing instrument and provide yet another source of potential error during the manufacturing process. The guide structures and complexity added can also increase problems with use or breakage of the writing instrument or lead during use, if the guide structure fails or breaks.
Accordingly, a need exists to create a simple, reliable, side-knock mechanism for mechanical pencils that overcomes one or more of the disadvantages of current designs.
In accordance with one embodiment of the disclosure, a writing instrument with a body, the body being a generally hollow tubular shape with an inner lumen, outer surface opposite the inner lumen, first end, and second end opposite the first end, a lead tube with a first tube end, a second tube end opposite the first tube end, and an outer tube surface, a knock button, coupled to the body, and a frustoconical hub, where the frustoconical hub is disposed around the outer tube surface of the lead tube and positioned along a length of the lead tube such that at least a portion of the knock button slides along the frustoconical hub when the knock button is actuated. The mechanism described herein allows the translation of the pivoting or rotational motion of the knock button actuation, to a linear motion of the lead tube.
In another embodiment of the disclosure, a writing instrument includes a body, the body is a generally hollow tube defining an inner lumen, an outer surface opposite the inner lumen, a first end, and a second end opposite the first end, where the first end is a writing end with a generally conical writing tip with a tip aperture, the body also includes an aperture extending between the outer surface and the inner lumen. The writing instrument also includes a lead tube with an inner tube lumen, outer tube surface opposite the inner tube lumen, and a frustoconical hub disposed around the outer tube surface, at least one writing medium, the writing medium being disposed within the inner lumen of the lead tube, and a knock button, where the knock button is disposed in the aperture of the body and is configured to slidably engage the frustoconical hub when actuated, sliding the lead tube towards the writing end.
The detailed description is set forth with reference to the accompanying drawings. The use of the same reference numerals may indicate similar or identical items. Various embodiments may utilize elements and/or components other than those illustrated in the drawings, and some elements and/or components may not be present in various embodiments. Elements and/or components in the figures are not necessarily drawn to scale. Throughout this disclosure, depending on the context, singular and plural terminology may be used interchangeably.
The writing instruments and side knock button mechanisms described herein advantageously can accommodate various writing mediums. The present disclosure includes non-limiting embodiments of writing instruments and side-knock button mechanisms. The embodiments are described in detail herein to enable one of ordinary skill in the art to practice the writing instruments and associated side-knock button mechanisms, although it is to be understood that other embodiments may be utilized and that logical changes may be made without departing from the scope of the disclosure. Reference is made herein to the accompanying drawings illustrating some embodiments of the disclosure, in which use of the same reference numerals indicates similar or identical items. Throughout the disclosure, depending on the context, singular and plural terminology may be used interchangeably.
The meanings of the terms used herein will be apparent to one of ordinary skill in the art or will become apparent to one of ordinary skill in the art upon review of the detailed description when taken in conjunction with the several drawings and the appended claims. While certain discussion is made herein with respect to pencil lead, it should be understood that the present disclosure could be used with other writing mediums within the scope of the present disclosure. As used herein, the terms “connect,” “mount,” “couple,” and other similar terms are used broadly to refer to any suitable direct or indirect connection mechanism.
Throughout this disclosure, various aspects of this disclosure are presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.
As shown in
In some embodiments, the sliding surface 300 originates at a distance from the top surface 270 of the knock button 200, creating a front surface 310 at the front end 250 of the knock button 200, as shown in
The lead tube 160 houses lead or other writing mediums and actuates to deliver the writing medium to the writing tip of the writing instrument 100. As illustrated in
Interaction between the knock button 200 and a frustoconical hub 210 for actuation of the lead tube 160 prevents the need for any guide structures to be added to the lead tube 160 or body 110 to prevent rotation of the lead tube 160 during cycling. The frustoconical hub 210 provides 360° of contact surfaces along which the sliding surface 300 of the knock button 200 can be guided during actuation. This advantageously greatly simplifies and reduces overall cost of the writing instrument. Unlike conventional side-knock writing instruments, assembly of writing instruments in accordance with embodiments of the disclosure only requires linear alignment of the frustoconical hub 210 with the knock button 200. Linear alignment can be achieved with the insertion of the lead tube 160 into the body 110, as the location of the frustoconical hub 210 on the lead tube 160 can be preselected based on the length of the lead tube 160 and the selected location of the knock button 200.
Certain embodiments of the writing instrument 100 include a knock button 200 that is pivotally mounted to the body 110 and that can pivot between a rest position and actuated position. In some embodiments the knock button 200 pivots about integrated protrusions that mate with the body. In other examples, the knock button 200 pivots about a pinned axis. Other methods of pivotally mounting the knock button 200 to the body 110 are contemplated herein. In one example, the knock button 200 is fixed at the front end 250 near the second end 150 of the body 110, and can be depressed near the front end 250 of the knock button 200 to actuate the knock button 200. The knock button 200 could also be fixed at the front end 250 and actuated by depressing the rear end 320 of the knock button 200. Referring again to
In some exemplary embodiments, as shown in
In another example embodiment, the writing instrument 100 includes a body 110 that is a generally hollow tube defining an inner lumen 120, an outer surface 130 opposite the inner lumen 120, a first end 140, and a second end 150 opposite the first end 140. The first end 140 is a writing end with a generally conical writing tip 145 and a tip aperture 155. The body 110 also includes an aperture 215 that extends between the outer surface 130 and the inner lumen 120. The writing instrument 100 may also include a lead tube 160 with an inner lumen 120, an outer tube surface 190 opposite the inner lumen, a frustoconical hub 210 disposed around the outer surface 130 of the lead tube 160, and a knock button 200. The knock button 200 may be disposed in the aperture 215 of the body 110, and be configured to slidably engage the frustoconical hub 210 when the knock button 200 is actuated, sliding the lead tube 160 toward the writing end 140.
In some embodiments, a return element 195 is included that biases the lead tube 160 back towards the second end 150 of the body 110. The writing instrument also includes a chuck that is configured to cooperate with and selectively grip the writing medium. When the knock button 200 is actuated, the lead tube 160 moves towards the first end of the body 110. As tension increases in the return element 195, it disengages the chuck, which allows the lead tube 160 to move rearward without retracting the writing medium when the knock button 200 is released. As shown in
The lead tube 160 must travel a sufficient distance to advance the lead and then release the lead chuck so as not to pull the lead backwards as the lead tube retracts. By changing the stroke of the lead tube 160 that results from the knock button 200 actuation, the number of times the knock button 200 must be pressed to extend a certain length of lead can be altered. For example, the desired actuation of the lead tube 160 can be between about 0.15 inches and about 0.20 inches, or between about 0.15 inches and about 0.175 inches, or between about 0.125 inches and about 0.20 inches.
Although certain embodiments of the disclosure are described herein and shown in the accompanying drawings, one of ordinary skill in the art will recognize that numerous modifications and alternative embodiments are within the scope of the disclosure. Moreover, although certain embodiments of the disclosure are described herein with respect to specific mechanisms and configurations, it will be appreciated that numerous other mechanisms and configurations are within the scope of the disclosure. Conditional language used herein, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, generally is intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, or functional capabilities. Thus, such conditional language generally is not intended to imply that certain features, elements, or functional capabilities are in any way required for all embodiments.
This application is a continuation of U.S. application Ser. No. 15/833,670, filed Dec. 6, 2017, which claims priority benefit of U.S. Provisional Application No. 62/430,676, titled “Writing Instrument” and filed on Dec. 6, 2016, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62430676 | Dec 2016 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15833670 | Dec 2017 | US |
| Child | 16696786 | US |
