Mechanical pencil

Claim 2

A writing instrument having lead or the like therein, comprising: means for releasibly holding lead, means for housing the lead holding means, means for moving the lead holding means axially downward in the housing means, means for signalling division of the axial movement into a first stroke region and a second sTroke region sequentially following the first stroke region, means for positioning the lead holding means for storage at the beginning of the first stroke region, the lead holding means for writing at the end of the first stroke region, and the lead holding means for feeding lead adjacent the end of the second stroke region; means for feeding lead through the lead holding means in the second stroke region, and means for requiring return of the lead holding means to said writing position after feeding lead through the lead holding means.

Claim 3

A writing instrument as recited in claim 1, wherein the lead holding means comprises a collet, and wherein the means for feeding lead comprises a locking sleeve releasibly affixed to the collet for movement therewith through said first stroke-region, and a shoulder fixed in the downward path of movement of the locking sleeve in position for preventing the locking sleeve from moving downward with the collet in said second stroke-region, thereby releasing the collet and the lead for feeding through the collet.

Claim 4

A writing instrument as recited in claim 2, wherein the locking sleeve has a flange thereon, wherein said shoulder fixed in the downward path of movement of the locking sleeve is fixed to the housing means, wherein the housing means has a second shoulder in the path of movement of the flange above the first said shoulder, wherein a first resilient compression means extends between the first said shoulder and the flange, and a second resilient compression means extends between the flange and the means for positioning, and wherein downward movement of the plunger means compresses at least one said resilient compression means moving the flange against the second shoulder, comprises the means for signalling division of the axial movement.

Claim 5

A writing instrument as recited in claim 2, wherein a sleeve having a flange surrounds the collet and locking sleeve, wherein said flanged sleeve bears said shoulder fixed in the downward path of movement of the locking sleeve and bears a second shoulder fixed in the upward path of movement of the locking sleeve wherein the housing means has an interior shoulder below the flange, wherein a first and relatively weak resilient compression means extends between the housing means interior shoulder and the flange, wherein a second and relatively strong resilient compression means extends between the flange and the means for positioning, wherein means is provided for connecting the means for moving and the means for positioning for thereby compressing all said resilient compression means on downward movement of the means for movement and whereby compression of the relatively weak resilient compression means to a predetermined length comprises the means for signalling division of the axial movement.

Claim 6

A writing instrument as recited in claim 4, wherein a lead support is affixed to the lower end of the flanged sleeve in coaxial alignment for passage of the lead therethrough, and wherein a resilient member is affixed within the lead support in position to retard movement of passing lead, whereby on incremental advance and release of lead by the collet the lead is fixed in position during retraction and re-engagement of the collet with the locking sleeve.

Claim 7

A writing instrument as recited in claim 1, wherein the means for moving the lead holding means comprises plunger means, wherein the means for positioning the lead holding means comprises a camway and a cam follower, means on the housing means and means on the plunger means fixing the camway and cam follower in radial, movable relation one to the other with one constrained for movement with the housing means and the other constrained for movement with the plunger means.

Claim 8

A writing instrument as recited in claim 6, wherein the camway comprises an assymmetrical lower cam element, an upper generally lenticular-shape cam element diagonally disposed above the lower cam element and perimeter structure defining together with the cam elements: a firSt channel generally upright one side of the cam elements turning inward over a portion of the side of the lower cam element toward the upper cam element and thereby comprising said means for requiring return of the lead holding means to said writing position, a second channel generally upright on the opposite side of all said cam elements with the first and second channels joining at the top, a third channel generally upwardly concave channel joining together the first and second channels at a location separating the upper cam element as an island cam.

Claim 9

A writing instrument as recited in claim 6, wherein the engagement position of the cam follower with the third channel defines the extended-for-writing position of the lead holding means, wherein the engagement position of the cam follower with a lower portion of at least one of the generally upright channels comprises the means for positioning the lead holding means for storage, and wherein the engagement of the cam follower with the upper portion of either the first or second channel adjacent the top of the upper cam element comprises the means for positioning the lead holding means for feeding lead.

Claim 10

A writing instrument as recited in claim 7, and structure forming a downward facing hook shape in a channel portion above the upper cam element, thereby guiding relative travel of the cam follower from the storage position directly to the lead feed position.

Claim 11

A writing instrument as recited in claim 9, wherein said structure forms the hook shape in the inward turned portion of the first channel.

Claim 12

A writing instrument as recited in claim 9, wherein said structure forms the hook shape in the lower periphery of the upper cam element.

Claim 13

A writing instrument as recited in claim 7, wherein a plurality of said camways is provided in lateral juxtaposition, each said camway having a channel interconnection on each side with an adjacent said camway.

Claim 14

A writing instrument as recited in claim 12, wherein said channel interconnection comprises merger of one of said generally upright channels with a next adjacent generally upright channel at the conjuncture of said third channel wherein structure is provided defining a slope of a portion of said third channel adjacent said conjuncture, thereby providing for operative serial transfer of the camways past the cam follower.

Claim 15

A writing instrument as recited in claim 13, wherein structure is provided defining a filler slot connection with at least one of said channels.

Claim 16

A writing instrument as recited in claim 7, wherein structure is provided defining a vertical channel extending from said inward turned portion of the first channel to a position above the upward extent of the upper cam element.

Claim 17

A writing instrument as recited in claim 15, wherein in a plurality of said camways is provided, each said camway having a channel interconnection on each side with an adjacent said camway.

Claim 18

A writing instrument as recited in claim 7, wherein structure is provided joining the first and second said channels in ''''V'''' configuration below the lower element, and wherein the bottom portion of the lower cam element is laterally offset with respect to the V configuration, thereby providing for the first said channel to descend past the cam follower on operation beginning with the storage position.

Claim 19

A writing instrument as recited in claim 17, wherein a plurality of camways is provided in lateral juxtaposition, each said camway having a channel interconnection on each side with an adjacent said camway.

Claim 20

A writing instrument as recited in claim 17, wherein structure is provided defining a bellmouth filler slot connection with at least one of said channels.

Claim 21

A writing instrument as recited in claim 7, wherein structure is provided defining the lower portions of the first and second generally upright channels as substantially straight and parallel with the lower ends closed, the lower cam element thereby being in the form of a peninSula.

Claim 22

A writing instrument as recited in claim 20, wherein a plurality of said camways is provided in lateral juxtaposition, each said camway having a channel interconnection on each side to an adjacent said camway.

Claim 23

A writing instrument as recited in claim 6, wherein the cam follower extends radially inwardly and the means on the housing means fixes the cam follower to the housing means, and wherein the camway comprises an exterior cylindrical surface and the means on the plunger means fixes the camway to the plunger means.

Claim 24

A writing instrument as recited in claim 6, wherein the camway comprises an interior cylindrical surface and the means on the housing means fix the camway to the housing means, and wherein the cam follower extends radially outwardly and the means on the plunger means fixes the cam follower to the plunger means.

Claim 25

A writing instrument as recited in claim 6, wherein the cam follower comprises at least one inward protrusion affixed in the inner surface of the upper part of the housing means.

Claim 26

A writing instrument as recited in claim 24, wherein the upper part of the housing means is divided into the shape of a fork, wherein the inward protrusion is affixed to one part of the fork, and wherein a second inward protrusion is provided affixed to a second part of the fork.

Claim 27

A writing instrument as recited in claim 6, wherein the means on the housing means comprises an annular-recess.

Claim 28

A writing instrument as recited in claim 26, wherein the means on the plunger means comprises a flange integral with the plunger means.

Claim 29

A writing instrument as recited in claim 27, wherein a circular shape holder retained in the annular recess in the housing means secures the cam follower in the inner surface of the circular shape holder and wherein the camway comprises an exterior cylindrical surface movable with the plunger means.

Claim 30

A writing instrument as recited in claim 28, wherein the circular shape holder has a resilient arm attached thereto, and wherein the cam follower is affixed to the resilient arm.

Claim 31

A writing instrument as recited in claim 27, wherein the circular shape holder comprises a snapring.

Claim 32

A writing instrument as recited in claim 27, wherein the circular shape holder includes a recess in the inner face receiving the cam follower.

Claim 33

A writing instrument as recited in claim 31, wherein recess is annular and wherein the cam follower comprises a sphere movable in said annular recess.

Claim 34

A writing instrument as recited in claim 30, wherein the recess is radial and wherein the cam follower comprises an elongate member movable in said radial recess.

Claim 35

A writing instrument as recited in claim 26, wherein the housing means is divided transversely at said recess and has internal threads in the divided parts of the recess, wherein a cylindrical member secures the cam follower in the inner face thereof, and wherein the cylindrical member has external threads dimensioned for uniting the threaded divided parts of the housing means.

Claim 36

A writing instrument as recited in claim 6, wherein a circular shape holder engages the flange of the plunger means and wherein the cam follower protrudes outwardly from the circular shape holder.

Claim 37

A writing instrument as recited in claim 35, wherein the circular shape holder is a snapring.

Claim 38

A writing instrument as recited in claim 35, wherein the circular shape holder has a recess therein receiving the cam follower.

Claim 39

A writing instrument as recited in claim 37, wherein the recess is annular, and wherein the cam follower is a sphere movable in said annular recess.

Claim 40

A writing instrument as recited in claim 37, wherein the recess is radial and wherein the cam follower comprises an elongate member movable in said radial recess.

Claim 41

A writing instrument as recited in claim 6, wherein the camway comprises an inward facing integral part of the interior surface of the housing means.

Claim 42

A writing instrument as recited in claim 26, whereiN the camway comprises an inward facing portion of a cylindrical sleeve divided longitudinally into plural parts and wherein the plural parts are retained in the annular recess in the housing means and means for requiring return of the lead holding means to said writing position after feeding lead through the lead holding means.