Technical Field This invention relates generally to implement closures, and more particularly to protective closures for writing implements, being strikingly suitable for use therewith.

Background Art It is common practice, especially in pen design and construction, to provide protective means to safeguard the writing tip of the implement when not in use and to prevent marking of unintended objects such as shirt pockets. A removable cap is commonplace, as are the more costly and complex writing implements having one of .a variety of transmission mechanisms for moving the writing tip in and out .of register with a protective barrel member.

Inherent drawbacks to the above methods include cap loss and displacement or mechanical failure, as well as higher complexity and cost of the transmission mechanism employed. Accordingly, it has been the purpose of several existing closure devices, and implements incorporating the same, to provide an alternative to both the removable cap and commonly employed transmission mechanisms as means for protecting and exposing the tip of implements such as pens or pencils. Representative of such devices are Zepelovitch, U.S. Patent No. 2,559,555 and Vogel, U.S.

Patent No . 3 , 311, 089.

A typical alternative, as demonstrated in the Zepelovitch patent, is the axially displaceable closure mounted upon the writing implement in the vicinity of the writing tip. Meant to be carried and retained thereupon, the closure slides in its entirety from an advanced, covering position to a retracted, exposing position with respect to the writing tip. Additional members are provided to coact with corresponding implement members as keepers, controlling the extent of movement and preventing unwanted retraction or removal of the closure.

Another alternative, as demonstrated in the Vogel patent, is a contracting casing for housing a conventional writing element or cartridge therein. In this patent, a forward casing portion is adapted for axial movement toward a rearward casing portion, thereby outwardly projecting or otherwise deforming a flexible intermediate casing portion intended for this purpose. Being axially stationary therein, the writing means of the cartridge is projected beyond the implement through a forward opening. Additionally, according to Vogel, the achieved writing position is maintained by finger pressure transmitted through the forward casing portion to the writing cartridge, or is self-retained therein by frictional engagement between a restrictive forward opening and the cartridge member.

Disclosure of the Invention

In preferred embodiments thereof, the closure comprises a simply constructed sheath adapted for use with, and for attachment to, the body portion of an ordinary writing implement. While being stationarily carried upon the body portion of the implement in the vicinity of the writing tip, the closure provides both an enclosing first position and an exposing second position with respect to the writing tip. The closure.

having fold means, is so adapted to flexibly fold upon itself into a cross-sectionally continuous and self-retaining fold, not only contracting the length of the sheath thereby, but also retaining the sheath in its folded, contracted state.

Brief Description of the Drawing The invention can best be understood in conjunction with the accompanying drawing to which the description of preferred embodiments correspond. FIGURE 1 illustrates the retractable closure according to the preferred embodiment of the invention, the closure presented in partial section, in a relaxed state, and in covering relation to the forward end and writing tip of an ordinary writing implement. FIGURE 2 shows the closure according to FIGURE 1 retracted into an exposing position with respect to the writing tip of the implement.

FIGURE 3 is an illustration of an alternative embodiment of the closure. In partial section, the closure shows an inward folding of the sheath as opposed to an outward folding as illustrated in FIGURES 1 and 2. The closure in this embodiment also illustrates an alternate form of attachment between the closure and the body portion of the implement.

Best Mode of Carrying Out the Invention

Referring particularly to FIGURES 1 and 2, the closure comprises a sheath 10 of simple construction. One-piece in form, the sheath 10 is of tubular character, having both a longitudinal extent and a cross-sectionally continuous wall 12 providing an inner wall surface 20 and an outer wall surface 18. The sheath is substantially circular in cross section and provides a centrally open region and a central axis therein. The longitudinal extent of the sheath defines, by features of construction and intent of purpose, a

forward sheath section 16 adapted for linear movement with respect to the underlying elements of the implement, an intermediate wall portion designated as an inclining wall portion 26, and a rearward sheath secion 14 meant for a stationary relation to the body portion of the implement, as will be discussed later in greater detail. The material used in the consruction of the sheath 10 is preferably both resilient and foldable in nature, being capable of sustaining a given shape and again recovering its shape having been folded or otherwise deformed.

The sheath 10 is shown in an attached relation to the body portion 42 of a writing implement 40. FIGURE 1 shows the sheath in its relaxed state and in an enclosing first position with respect to the forward end 44 and tip 46 of the implement. In contrast, FIGURE 2 shows the sheath in its contracted state and in an exposing second position with respect to the same. The writing implement is itself of known construction as a common lead pencil. A pencil is used by way of example only, as an ink pen or other similarly constructed implement could be used representatively and in keeping with the scope of the invention.

Continuing in more detail, the sheath 10 further comprises both a forward opening 22 and a rearward opening 24 by which the centrally open region within the sheath wall 12 communicates with the region outside the sheath wall, as when unattached to the implement 40. Through the rearward opening 24 of the sheath, to within the centrally open region therein, is placed the forward end 44 and writing tip 46 of the implement. The writing tip 46 normally does not extend through the forward opening 22 of the sheath while the sheath is in its relaxed state but does so when the sheath is in its contracted state. Forming an attached relation to the implement body portion 42, the rearward sheath section 14 is carried thereupon in the vicinity of its forward

end 44. This attached relation is understood as stationary during both the enclosing and the exposing postions of the sheath. However, the sheath may be removed as needed, as when sharpening the implement, replacing a tip, or transfering to another implement.

The attached relation itself comprises a substantially snug fit between the inner wall surface 20 of the rearward sheath section 14 and the body portion 42 of the implement 40, as the sheath is sized to snugly conform about the perimeter of the implement. The foldably resilient nature of the sheath may act to accomplish this snug fitting by expanding somewhat in accommodation of the implement body portion.

Comparative scrutiny of both FIGURES 1 and 2 reveals the means by which the sheath achieves contraction in its conversion from a relaxed state to a contracted state. Again, when employee! to use, the sheath 10, more specifically the rearward section 14 thereof, forms an attached and stationary relation to the body portion 42 of the implement 40. In contrast, the remainder of the sheath, the forward sheath section 16 and an intermediately positioned inclining wall portion 26, is sufficiently enlarged and so configured as to avoid restriction of movement between it and the forward end 44 and writing tip 46 of the implement.

This is particularly achieved by the cross-sectional and longitudinal configuration of the sheath in its forward section, being of a substantially conical configuration. As shown, the forward sheath section 16 is conically largest in the vicinity of, and with respect to, the rearward sheath section 14 and conically smallest in the vicinity of the forward opening 22. Conforming about the end and writing tip of the implement thereat in spaced-apart relation, the forward sheath section 16, so configured, further defines an inclining wall portion 26 leading from the comparatively smaller rearward sheath section 14 to the comparatively larger portion of the

sheath, the forward sheath section 16. Recalling the cross-sectionally continuous extent of the sheath wall 12, it can readily be appreciated that the respective angular intersections 28 and 30 provided along the sheath wall for defining the inclining wall portion 26 will effectively bias the sheath to alter in degree of angulation thereat when the forward 16 and rearward 24 sections of the sheath are manually urged toward each other. A cross-sectionally continuous fold 32 is therefore established as the inclining wall portion 26 folds backward and reverses in direction, thereby substantially approximating its inner wall surface with that of a portion of the forward sheath section 16 and substantially approximating its outerwall surface with that of a portion of the rearward sheath section 14.

FIGURE 2 provides the illustration of the sheath having been adjusted longitudinally from its normally extended position and relaxed state (shown in phantom outline) into its retracted position and.folded state. Preceeding further, the means by which the sheath is adapted to maintain and reverse its folded, contracted state is as follows: The forward sheath section 16 is enlarged rearwardly in size only to an extent as to closely conform about both the inclining wall portion 26 and the forward portion of the rearward sheath section 14 when the fold 32 is achieved. In this way, the now reversed inclining wall porion 26 is constrictively held between overlapping portions of the sheath, resisting the tendency for the sheath to return to its usual extended position. Reversing the achieved fold 32 is a matter of manually urging the opposing rearward 14 and forward 16 sections apart, returning the sheath 10 again to its relaxed state and extended position. It is of note that certain variations in construction and design will influence the function of the closure. For example, varying the length or the

degree of incline of the inclining wall portion 26 will vary the extent of sheath contraction. Also, the degree of resiliency or foldability of the sheath will affect its operation. On one hand, the sheath may be of such a degree of resiliency as to provide a distinct snap-action characteristic during sheath contraction. On the other hand, a lesser degree of resiliency will provide a more rolling action when the sheath is urged into a contracted state. The basic principles demonstrated in FIGURES 1 and

2 give rise to variations in design and construction. FIGURE 3 illustrates such an example of an alternative embodiment of the invention.

Presented in partial section and in attached relation to the body portion 82 of a writing implement 80, the sheath 60 in FIGURE 3 is adapted to fold upon itself in an inward fashion. The forward sheath section 64 is illustrated in its contracted state and exposing second position with respect to the forward end 88 and writing tip 90 of the implement. The implement in this figure can be recognized as an ink pen. In phantom outling, the forward sheath section 64 is illustrated as it would appear when the sheath is in a relaxed state and in an enclosing first position with respect to the writing tip 90 of the implement. The construction of the sheath is somewhat the same and of like function as seen in the embodiment according to FIGURES 1 and 2. The forward sheath section 64 is adapted for axial movement toward a stationarily maintained rearward sheath section 62 and achieves a cross-sectionally continuous fold 72 when the inclining wall portion 66 is reversed in direction. In this embodiment, the inclining wall portion 66 inclines upwardly from an comparatively smaller forward sheath section 64 to a comparatively larger rearward sheath section 62, and adapts the sheath to fold inwardly within itself when the sheath is urged into a contracted state. As in the first presented

embodiment of the invention, the inclining wall portion 66, once reversed in direction, is constrictively held between overlapping sections of the sheath until manual reduction of the fold 72 is performed. The attachment between the sheath 60 and the implement 80 in the embodiment of FIGURE 3 can be seen as an alternative to the attachment means in FIGURES 1 and 2. An annular tongue 70, formed on the inside of the rearward sheath section 62 is provided to mate with the annular groove provided in a forward part of the body portion 82 of the implement. Such a tongue and groove arrangement would provide a snap-into-position alternative when mounting the closure to the implement and would help maintain the closure in place upon the implement during use.

Industrial Applicability From the foregoing description of the invention it can be readily appreciated that the art has been significantly advanced thereby. Not only can the closure be fashioned from a wide range of elastically deformable substances by simple molding techniques, but it can be inexpensively made and simply attached to an implement. The closure could be marketed separately or together with an associated implement. Also, the closure could be of various colors, different variations in design, or of an assortment of textures which would appeal to the tastes of the consumer.

Conclusion As can be recognized, the sheath according to the invention can be of several embodiments or variations.

Although described representatively in relation to writing implements, other devices of similar construction needing end-point protection can be improved and benefited by the present invention. In addition, the closure itself, as well as an implement

unitarily incorporating the same, is within the spirit and scope of the invention.