Tool incorporating writing mechanism

A tool according to the invention includes elements adapted to achieve a primary function of the tool, and further includes a writing element adapted to achieve a writing function. In one example, the tool is a screwdriver, and the writing element comprises a pencil lead that can be extended from the head end of the screwdriver to achieve a writing function, and retracted within the head end of the screwdriver to perform a screwdriving function.

FIELD OF THE INVENTION
 This invention is directed to the field of tools, such as screwdrivers.
 BACKGROUND OF THE INVENTION
 Carpenters, at-home handy-men and women, and others frequently use a
 plurality of tools to accomplish a task, such as driving a screw, as part
 of the accomplishment of an overall project. An example of a common
 project is the project of hanging a picture or mirror on a wall.
 Frequently, the weight of the picture or mirror to be hung on the wall
 mandates that the picture or mirror be hung from a screw or nail driven
 into a stud behind finished drywall. A stud detector is a known device
 that enables a user to determine the location of studs behind the finished
 drywall.
 It is frequently inconvenient, when a person is attempting to accomplish
 such a task, for the person to realize that in assembling the required
 tools to accomplish the task the person neglected to provide a marking
 instrument, such as a pencil, for use in marking the location of the stud.
 This inconvenience is heightened if the person is on top of a ladder or in
 some other out-of-the-way position, from which there is no easy access to
 a workbench, desk or other location at which a pencil could be found. The
 person accomplishing the task must thus climb down the ladder and locate a
 pencil, then climb back up the ladder to continue the task.
 The aforementioned project is but one example of a project where a marking
 instrument is necessary in conjunction with conventional tools. In
 addition to the requirement to assemble the proper tools and instruments,
 it is also frequently necessary and inconvenient for a person, when in a
 precarious position, such as at or near the top of a ladder, to maneuver a
 plurality of instruments, including, for example, some or all of the
 following: a screwdriver and screws, a hammer and nails, a level, a stud
 detector, a tape measure, a paint brush and paint, or any other set of
 tools and materials associated with a project, while simultaneously
 maneuvering a pencil or other writing instrument in order to mark a stud
 point, to mark a level point, to record a measurement of length, or for
 any other purpose for which a pencil is conventionally employed during a
 home project. It is not uncommon for a pencil to be precariously
 positioned on a ladder step or shelf while the person performs a task with
 another tool, and for the pencil to then roll off the step or shelf while
 the task is being performed, requiring the person to interrupt the task in
 order to retrieve the pencil.
 SUMMARY OF THE INVENTION
 The invention solves this problem by incorporating a writing
 instrumentality into a tool, such as a screwdriver. Accordingly, a tool
 according to the invention includes elements adapted to achieve a primary
 function of the tool, and further includes a writing element adapted to
 achieve a writing function. In one example, the tool is a screwdriver, and
 the writing element comprises a pencil lead that can be extended from the
 head end of the screwdriver to achieve a writing function, and retracted
 within the head end of the screwdriver to perform a screwdriving function.

DETAILED DESCRIPTION
 FIG. 6 is a rough sketch of a conventional screwdriver 602 including a
 handle 604, a shaft 606, and a head 608. Conventionally, handle 604 is
 made from a plastic or rubber material, while shaft 606 and head 608 are
 integrally formed from a metal material, such as steel. Typically, an end
 610 of shaft 606 opposite head 608 is affixed inside an orifice 612 of
 handle 604 to couple shaft 606 (and hence head 608) to handle 604. To
 facilitate this coupling, shaft 606 may include one or more wings 614 to
 tap into handle 604 or to mate with grooves formed therein.
 FIG. 7 is a rough sketch of a cross-section of head 608 taken along the
 Y--Y plane (FIG. 6) of a conventional #2 Phillips-head screwdriver.
 Flanges 702, 704, 706 and 708 radiate from a central region 710. Flanges
 702-708 are positioned to mate with corresponding grooves in a
 conventional #2 Philips screw.
 FIG. 1 is a rough sketch of a corresponding cross-section for a screwdriver
 head 100 according to the invention. Here, flanges 102, 104, 106 and 108
 perform like functions to flanges 702-708 of FIG. 7. In contrast to the
 screwdriver shown in FIG. 7, however, a portion of central region 710 is
 replaced with an opening 110 sized to accommodate a writing element, such
 as a pencil lead, such as a 0.5 mm pencil lead.
 FIG. 2 is a rough sketch of a screwdriver 105 according to the invention,
 including head 100 having opening 110, a handle 107, and a shaft 109.
 Opening 110 is in communication with a chamber 111 internal to shaft 109.
 According to the invention, a lead holding element is positioned in
 chamber 111. In one embodiment according to the invention, chamber 111 is
 aligned with a similar chamber through handle 107, such that the lead
 holding element may be positioned within both handle 107 and shaft 109.
 The design and structure of lead holding elements are known. Preferably,
 the chamber 111 is sized to accommodate a conventional lead holding
 element as used in conventional mechanical pencils, such as the 0.5 mm
 Pentel P205.
 FIG. 3 is a rough sketch of an exemplary embodiment, wherein handle 107
 includes a cap 301 positioned in a corresponding hole 303. For example,
 cap 301 may be threaded into hole 303. Alternatively, cap 301 may be snap
 fit or frictionally fit into hole 303 or may be snap or frictionally fit
 onto a lead holding element, a portion of which is stored within handle
 107. In any event, cap 301 provides an avenue for access to the inside of
 opening 303 in order to add lead to the lead holding element, for example.
 Cap 301 may also be coupled to the lead holding element such that cap 301
 can be manipulated by a user to correspondingly suppress a spring portion
 of the lead holding element and to cause a portion of a lead to be
 displaced in a longitudinal direction toward or out of opening 110. The
 coupling of a cap to a lead holding element is known to one of skill in
 the an of mechanical pencils. In the illustrative embodiment, cap 301 is
 coupled to the lead holding element accordingly. Continued suppression of
 cap 301 will thus cause a lead to be extended from (i.e. to be clicked out
 of) opening 110.
 When finished writing, and/or when screwdriver 105 is needed to drive a
 screw, cap 301 can be suppressed in concert with inward pressure on the
 extended lead, to thereby cause the lead to be retracted into the lead
 holding element. This procedure can be managed, for example, by
 suppressing cap 301 while simultaneously placing head 100 into a screw to
 be driven. As pressure is placed on the screw by head 100, corresponding
 pressure will push the lead back into the lead holding element.
 The use of cap 301 as both an entry vehicle into the inside of handle 107,
 and also as a lead extending element manipulable by the user is purely by
 way of example, and not of limitation. It is of course possible for the
 lead extending element to be separate from the cap 301. For example, as
 shown in FIG. 4, the lead extending element can include a button 402
 positioned along the side of shaft 109 and coupled to a translating
 element 404 through which suppression of button 402 is translated into
 longitudinal motion of a lead held by the lead holding element. An example
 of such a translating element can be seen in the Sanford Clickster
 mechanical pencil.
 The lead holding elements described above advance the lead by clicking the
 lead out through opening 10. Alternatively, the lead holding element can
 be screw driven, whereby the lead is advanced and retracted by a screwing
 action. in a manner which is also employed in conventional mechanical
 pencils. For example, cap 301 can be press fit onto the lead holding
 element, and can be manipulable by the user such that when the user twists
 the cap 301 in one direction, such as the clockwise direction, the lead
 extends through and out of opening 110, and when the user twists cap 301
 in the other direction, such as the counterclockwise direction, the lead
 retracts through opening 110 and back into the lead holding element.
 Cap 301 may also be used in the manufacture of tool 105 to enable insertion
 of the lead holding element. The lead holding element can be press fit
 into chamber 111, by a conventional technique as known to one of skill in
 the art or may be configured to screw into a portion of chamber 111,
 either by mating with corresponding threads or by self tapping.
 Shaft 109 and head 100 may be integrally formed from steel, or may
 alternatively be formed from titanium or a hard composite. Chamber 111 may
 be formed in shaft 109 as part of the step of manufacturing shaft 109.
 Alternatively, shaft 109 may be formed in a conventional manner, and
 subsequently drilled and/or tapped to produce chamber 111 and opening 110.
 The material selected for shaft 109 and head 100 should be sufficiently
 strong so that head 100 can accommodate torque forces encountered when
 driving a screw, given the "loss" in material associated with opening 110
 when compared to central region 710. The strength and composition of the
 lead passing through opening 110, as well as its size with respect to
 opening 110, may also be selected to increase the overall strength of head
 100 when the lead is present in, but not extending from, opening 110.
 FIG. 5 is a rough sketch showing an exemplary lead holding element 501 for
 use as part of a tool according to the invention. Lead holding element
 501, in this exemplary embodiment is a conventional structure known to one
 of ordinary skill in the art. It includes a shaft 503 containing a lead
 storage cavity 504, a spring 505, a screw-in retaining portion 507, and a
 lead click passage 509 (shown in dotted lines) internal to spring 505 and
 screw-in retaining portion 507. The lead click passage 509 terminates in
 an expanding opening 511 comprising a plurality of sections that expand
 outwardly within opening 513 to allow lead to move therethrough.
 Operationally, screw-in retaining portion 507 mates with a corresponding
 threaded section inside chamber 111 near head 100 and retains lead holding
 element 501 within shaft 109. Shaft 503 mates with cap 301, for example,
 at a region 503a, illustratively, in a matter which is the same as that of
 a conventional mechanical pencil. Thus, when a user presses on cap 301,
 the force on cap 301 is transferred to shaft 503, compresses spring 505,
 and causes the lead passage 509 to move relative to screw-in retaining
 portion 507, thus causing the sections of expanding opening 511 to open
 and allow the lead to "click" out one incremental distance toward or
 through opening 110. Additional presses on cap 301 will allow the user to
 select the distance the lead travels through and out of opening 110.
 When the user is finished marking, and wants to return the lead to a
 position internal to head 100 so that the user can use screwdriver 105 for
 its primary purpose of driving a screw, the user simply maintains pressure
 on cap 301, causing sections of expanding opening 511 to move into and
 remain in the expanded position, while applying inward force to the lead,
 such as by pushing the lead in with the user's hand, or by pressing head
 100 into a screw.
 The invention is thus described with respect to a standard #2 Phillips-head
 screwdriver. This is purely by way of example and not of limitation. Also,
 the description above describes embodiments of the invention wherein the
 lead extends from the head end of a Philips-head screwdriver. This is also
 by way of example and not of limitation. For example, the writing element
 can extend from the handle portion of a screwdriver or from a different
 tool. Further, although lead is described as the writing material, other
 writing materials such as ink, chalk, paint, pastels, crayons, etc. may be
 employed.
 The invention can also be realized by incorporating a writing element into
 any tool. The advantage of the screwdriver as an exemplary embodiment is
 that the screwdriver presents a longitudinal profile with an elongated
 shaft, and modification of a conventional screwdriver to incorporate a
 writing element according to the invention is fairly easy to comprehend
 and visualize once the overall concept of the invention is understood.
 Further, the #2 Phillips-head screwdriver is very common, and is an
 important element in a large percentage of handyman projects.