Patent Grant
9358828
The present invention relates to a mechanical pencil in which a writing lead (refill lead) can easily be supplied and the supplied writing lead is inched out of a base member to allow writing at once.
As is well known, a knock-type mechanical pencil in which a cap as a knock cover is detachably attached to a rear end portion of a body cylinder. As this cap is knocked in the axial direction, a writing lead (refill lead) accommodated in a lead case within a body cylinder is gradually inched out of a base member at a tip end side of the body cylinder by the action of a lead fixing chuck and a holder chuck.
In this case, when the writing lead is consumed and another writing lead is supplied, the above-mentioned cap is removed and the new writing lead is supplied to a feeding unit at a rear end portion of the lead case, and it is necessary to reattach the above-mentioned cap to the rear end portion of the body cylinder. Further, in addition to attachment/detachment operation of the above-mentioned cap, attachment/detachment operation of an eraser is also needed in the mechanical pencil in which the eraser is provided within the above-mentioned cap.
After supplying the writing lead, by repeating the knock operation of the above-mentioned reattached cap, the supplied writing lead is gradually inched out of a writing lead outlet of a pipe end projecting from the base member, for example, thus resulting in a situation where writing is allowed.
As described above, according to the conventional knock-type mechanical pencil, after recognizing that the writing lead has been consumed, a new writing lead is supplied. Thus, removal or reattachment of the cap and a number of knock operations are needed until the writing lead is inched out in order to allow writing again, which is troublesome for anybody.
Then, the present applicant has proposed previously a mechanical pencil in which removal or reattachement of the cap can be omitted when supplying the writing lead, which is disclosed in Patent Document 1.
Patent Document 1: Japanese Patent Application Publication No. 2000-127673
According to the mechanical pencil disclosed in Patent Document above, it is arranged that the writing lead feeding unit is opened by rotating the cap in the circumferential direction by a half revolution, so that the writing lead can easily be supplied, without removing or reattaching the cap.
However, as is conventional, a number of knock operations are required until the writing lead is inched from the above-mentioned writing lead outlet, such as a pipe end, after supplying the writing lead.
The present invention aims to provide a mechanical pencil in which removal or reattachment of a cap can be avoided when supplying the writing lead, and after supplying the writing lead, the thus supplied writing lead can be inched out of the writing lead outlet, such as a pipe end, by a few knock operations, for example.
The mechanical pencil in accordance with the present invention made in order to solve the above-mentioned problems is a mechanical pencil having a lead fixing chuck which is moved back and forth in conjunction with knock operation of a knock bar to grasp and release a writing lead and a holder chuck which is provided in front of the above-mentioned lead fixing chuck and holds the above-mentioned writing lead frictionally so that the above-mentioned writing lead can be gradually inched out by repeating the above-mentioned knock operation, wherein an open/close mechanism for a writing lead feeding unit is provided in which the writing lead feeding unit for the above-mentioned writing lead is opened in a situation where a grip of the above-mentioned lead fixing chuck on the writing lead is released by the above-mentioned knock operation, and the above-mentioned holder chuck is disposed proximate to an outlet for the above-mentioned writing lead.
In this case, the open/close mechanism for the writing lead feeding unit in one preferred embodiment is constituted by a knock cover which is attached to the above-mentioned knock bar and has a writing lead inserting pipe in an axial direction, and an open/close valve which is made of a flexible material and through which a tip portion of the above-mentioned writing lead inserting pipe is inserted by forward movement by knock operation of the above-mentioned knock cover to open the lead feeding unit.
In addition, it is desirable that the above-mentioned open/close valve is formed by providing a thin film of a rubber material with a slit, and a tip portion of the above-mentioned writing lead inserting pipe provided for the above-mentioned knock cover is inserted into the above-mentioned slit of the rubber material by the above-mentioned knock operation to open the writing lead feeding unit.
Further, the open/close mechanism for the writing lead feeding unit in another preferred embodiment is arranged such that the above-mentioned knock bar may be rotationally driven and moved in the axial direction by knock operation, and an opening formed at the above-mentioned knock bar side and an opening formed at a knock cover side attached to the above-mentioned knock bar are aligned in the axial direction so as to open the writing lead feeding unit.
In this case, it is desirable that the above-mentioned knock bar is subjected to knock operation and locked in a situation where it has moved forward in the axial direction, then subjected to knock operation again and retreats in the axial direction to be unlocked, the writing lead feeding unit is opened, and the grip of the above-mentioned lead fixing chuck on the writing lead is released in the locked situation where the above-mentioned knock bar has moved forward in the axial direction.
As described above, according to the mechanical pencil in accordance with the present invention, since it is arranged that the grip of the lead fixing chuck on the writing lead is released by knock operation and the writing lead feeding unit is opened, the writing lead supplied through the above-mentioned feeding unit enters as it is by gravity in the lead fixing chuck in a situation where the grip is released.
Furthermore, since the holder chuck which holds the writing lead by friction is disposed proximate to the writing lead outlet, such as for example a pipe end which projects from the base member, the tip portion of the supplied writing lead immediately reaches this holder chuck portion.
Therefore, the tip portion of the supplied writing lead can be inched from the above-mentioned outlet by knocking the knock cover twice or so, resulting in a situation where writing is allowed. Thus, when supplying the writing lead, it is possible to avoid conventional removal or reattachment of a cap and the knock operation that has been necessarily repeated many times, and troublesome operations experienced when supplying the writing lead can be avoided.
Hereinafter, a mechanical pencil in accordance with the present invention will be described with reference to the preferred embodiments illustrated in the drawings. In each of the drawings as illustrated below, like parts or those achieve like functions are referred to by like reference signs, but reference signs are assigned to typical parts in some drawings, and the detailed structures may be described with reference to reference signs used in other drawings for the sake of brevity.
Firstly,
In this lead fixing chuck 4, a through hole is formed along its axis, and its tip portion made of brass is divided into a plurality of pieces. The divided tip pieces are loosely fitted in a brass clamp 5 formed in the shape of a ring. Further, the above-mentioned ring-shaped clamp 5 is fitted inside a tip portion of a rotatable cam 6 which is arranged to cover the perimeter of the above-mentioned lead fixing chuck 4 and which is formed in the shape of a cylinder.
As shown also in
According to the above-described structure, a linear lead-inserting hole from the lead case 3 to the writing lead outlet of the pipe end 7 is formed via a through hole formed in the lead fixing chuck 4 and through holes formed in the above-mentioned pipe end 7 and the above-mentioned holder chuck 9. The writing lead (refill lead) to be set forth later is inserted into the linear lead-inserting hole. Further, a coil-like chuck spring 10 is disposed at a space part between the above-mentioned rotatable cam 6 and lead fixing chuck 4.
In addition, the above-mentioned chuck spring 10 is accommodated in the rotatable cam 6 in a situation where a rear end portion of the above-mentioned chuck spring 10 is in abutment with an end face of the above-mentioned lead case 3 and a front end portion of the above-mentioned chuck spring 10 is in abutment with an annular end face formed in the rotatable cam 6. Therefore, the lead fixing chuck 4 in the rotatable cam 6 is biased in a direction to retreat by the action of the above-mentioned chuck spring 10, and its tip portion is accommodated in the above-mentioned clamp 5, so that the writing lead is gripped in the through hole of the lead fixing chuck 4.
The above-mentioned rotatable cam 6 has a large diameter portion where a diameter at its central portion in the axial direction is enlarged. A number of cam faces in the shape of saw-tooth are continuously formed in a circle at one end face and the other end face of the large diameter portion, to constitute first and second rotatable cam faces.
On the other hand, at the rear end portion of the above-mentioned rotatable cam 6, an upper cam formation member 12 in the shape of a cylinder is provided in the body cylinder 1, so as to cover the back end of the above-mentioned rotatable cam 6. At a front end portion of the above-mentioned upper cam formation member 12, a first fixed cam face is formed to confront a first rotatable cam face in the above-mentioned rotatable cam 6.
Further, a lower cam formation member 13 is provided outside the above-mentioned rotatable cam 6, this lower cam formation member 13 is attached on the body cylinder 1 side, and the second fixed cam face is formed to confront the second rotatable cam face in the above-mentioned rotatable cam 6.
A number of cam faces in the shape of saw-tooth are continuously formed in a circle at the first and second fixed cam faces in the above-mentioned upper cam formation member 12 and the lower cam formation member 13. A pitch of these cams is arranged to be the same as that of the cams provided for the first and second rotatable cam faces in the above-mentioned rotatable cam 6 confronting the former cams.
In
The above-mentioned cushion spring 17 acts to bias the above-mentioned torque canceller 15 forward. It is arranged that the above-mentioned torque canceller 15 subjected to this bias force pushes the above-mentioned rotatable cam 6 to move forward.
Further, a cylindrical clip holder 21 which has formed a clip 21a integrally therewith is fitted into and attached to the rear end portion of the body cylinder 1. As shown also in
A short member 24 is attached to the above-mentioned knock bar 22. In the substantially central part of this short member 24, a face 24a which has formed a through hole in the center, i.e., an abutment face for abutment with the above-mentioned lead case 3 is formed, and a conical face 24b is formed at a rear end portion of the above-mentioned short member 24. A spring seat 25 whose diameter is somewhat reduced on its rear end portion side is provided at a rear portion of the above-mentioned short member 24. A rubber open/close valve 27 which constitutes an open/close mechanism for a writing lead feeding unit is disposed within a space of this spring seat 25 and behind the conical face 24b of the above-mentioned short member 24.
As shown in
Returning to
Furthermore, when in constant use, a tip portion of the writing lead inserting pipe 28b is adjusted so as not to reach the thin film 27a of the above-mentioned open/close valve 27 by the action of the above-mentioned return spring 29. That is to say, in this preferred embodiment, the open/close mechanism for the writing lead feeding unit is constituted by the inserting pipe 28b for the writing lead arranged at the knock cover 28 and the above-mentioned open/close valve 27 as the operation will be described in detail later.
According to the mechanical pencil having the above-described structure, in the case where the above-mentioned lead fixing chuck 4 is provided with the writing lead, knock operation of the above-mentioned knock cover 28 allows the writing lead to be gradually inched out of the writing lead outlet of the pipe end 7.
That is to say, as the above-mentioned knock cover 28 is knocked, the knock bar 22 moves forward, and the abutment face 24a of the short member 24 attached to the knock bar 22 pushes out the lead case 3 forward. Thus, as a tip portion of the lead fixing chuck 4 projects from the clamp 5, a grip on the writing lead is released. Further, as the above-mentioned knock operation is stopped, the lead case 3 is retreated by the body spring 23, and the lead fixing chuck 4 is retreated by the action of the chuck spring 10.
At this time, the writing lead is held by friction in the through hole formed in the holder chuck 9. In this situation, as the tip portion of the lead fixing chuck 4 is accommodated in the above-mentioned clamp 5, the chuck 4 again causes the writing lead to be in the gripped state. That is to say, by repeating the knock operation of the above-mentioned knock cover 28, the lead fixing chuck 4 is moved back and forth so that the writing lead is gripped and released, whereby the writing lead is gradually inched out of the writing lead outlet of the pipe end 7.
In addition, in this mechanical pencil, gripping the writing lead, the lead fixing chuck 4 is accommodated in the above-mentioned body cylinder 1 so that it can rotate about the axis together with the above-mentioned rotatable cam 6. The above-mentioned cushion spring 17 acts to urge the rotatable cam 6 forward via the above-mentioned torque canceller 15.
In this situation, when writing is carried out, i.e., when writing pressure is applied to the writing lead (not shown) which has projected from the pipe end 7, the above-mentioned lead fixing chuck 4 gripping the writing lead retreats slightly in the axial direction against the bias force of the cushion spring 17. In conjunction with this, the rotatable cam 6 also retreats in the axial direction. Therefore, the first rotatable cam faces formed in a circle in the rotatable cam 6 are brought into meshed engagement with the above-mentioned first fixed cam faces similarly formed in a circle, and the rotatable cam 6 is subjected to the rotational drive corresponding to a half-phase (half-pitch) of one tooth of the first rotatable cam face in one direction.
When the writing of one stroke finishes and the writing pressure to the writing lead is released, the rotatable cam 6 is moved forward slightly in the axial direction by the action of the above-mentioned cushion spring 17, and the second rotatable cam faces formed in a circle at the rotatable cam 6 are brought into meshed engagement with the above-mentioned second fixed cam faces similarly formed in a circle, whereby the rotatable cam 6 is again subjected to the rotational drive corresponding to a half-phase (half-pitch) of one tooth of the second rotatable cam face.
As described above, according to the above-mentioned mechanical pencil, in conjunction with the axially reciprocating motion of the rotatable cam 6 being subjected to the writing pressure, the rotatable cam 6 is intermittently and rotationally driven in one way. Thus, the tip portion of the writing lead is always caused to be in the shape of a cone by wearing due to the writing and by the rotational motion applied to itself. Thus, it is possible to prevent the writing lead from being locally abraded as the writing proceeds and allow the writing with a stable line width.
Further, the whole lead L is operated by a fingertip to enter the lead inserting pipe 28b, so that the lead tip enters the lead case 3. In this situation, the lead L is held by the slit 27b in the open/close valve 27.
According to this operation, the tip portion of the writing lead inserting pipe 28b formed in the knock cover 28 moves into the slit 27b formed in the thin film 27a of the open/close valve 27.
Thereby, the open/close mechanism for the writing lead feeding unit is opened, and the lead L held by the slit 27b of the open/close valve 27 falls toward the lead fixing chuck 4 side by gravity. At this time, since the lead fixing chuck 4 is left released, the tip portion of the writing lead L immediately reaches (falls in) a position where the holder chuck 9 is disposed proximate to the writing lead outlet of the pipe end 7. As described above, with reference to
Therefore, the tip portion of the supplied writing lead L immediately reaches the position where the holder chuck 9 is disposed proximate to the writing lead outlet of the pipe end 7. So, then the knock cover is knocked one or two times, so that the lead fixing chuck 4 and the holder chuck 9 act to inch out the writing lead L, and the tip portion of the writing lead L is inched from the pipe end 7, thus allowing writing at once.
Next,
It is arranged that the knock cover 28 and the knock bar 22 of the mechanical pencil in the second preferred embodiment are locked in a situation where, upon knock operation, they have moved forward in the axial direction, and upon further knock operation they retreat in the axial direction to cancel the above-mentioned locked state.
As shown in
In this preferred embodiment, the above-mentioned locked state and the unlocked state are repeated alternately by knocking the above-mentioned knock cover 28. It is arranged that each time the above-mentioned locked state is switched to the unlocked state or vice-versa, the above-mentioned knock bar 22 side may be rotated about the axis by an angle of 45 degrees.
Further, the opening 31 formed in the knock cover 28 in the above-mentioned locked state and the opening 32 formed at the knock bar 22 side are in alignment with each other in the axial direction, and the writing lead feeding unit is opened. Furthermore, in the unlocked state, both the openings are not in alignment with each other in the axial direction, and the open/close mechanism for the writing lead feeding unit is closed. As described above, the writing lead is supplied in the locked state and in a situation where the writing lead feeding unit is opened, so that the writing lead immediately moves into the lead case 3 as shown in
On the other hand, four rib members 38 are circumferentially formed at regular intervals around the periphery of the knock bar indicated by reference number 22. A slope 38a is formed near a rear end of each rib member 38. The above-mentioned knock bar 22 is assembled in such a way that it is inserted into the opening at which the undulations 36 of the above-mentioned cylindrical body 34 are formed and the slope 38a of each rib member 38 may come into contact with the undulation 36 of the cylindrical body 34.
Further, an end face of a slide pipe 39 which is biased by the body spring 23 is brought into abutment with an opening around which the rib members 38 of the knock bar 22 are formed. That is to say, the body spring 23 is supported by the stopper member 14 which is fitted to a portion in the body cylinder 1, as shown in
As shown in
Eight projecting members 35 formed at the above-mentioned cylindrical body 34 enter and slide in the eight grooves 41 and 42 formed in the body cylinder 1. Therefore, the knock cover 28 attached to the cylindrical body 34 is slid only in the axial direction by knock operation, and cannot be rotated.
On the other hand, the rib member 38 of the knock bar 22 accommodated in the cylindrical body 34 falls into the deep groove 41 formed in the body cylinder 1 or it is brought into engagement with the wide slope 44.
For example, in the above-mentioned unlocked state, the rib member 38 of the above-mentioned knock bar 22 falls into the deep groove 41 formed in the body cylinder 1, and the knock bar 22 together with the knock cover 28 is caused to project from the rear end portion of the body cylinder. At this time, the open/close mechanism for the writing lead feeding unit is left closed.
In this state, as the knock cover 28 is knocked, the rib member 38 of the knock bar 22 is pushed and moved forward by the undulations 36 of the cylindrical body 34, and caused by the action of the undulations 36 and slope 38a to ride up the wide slope 44 formed at the body cylinder 1. At this time, the knock bar 22 axially rotates by 45 degrees and caused to be in the above-mentioned locked state. At this time, the open/close mechanism for the writing lead feeding unit is left opened.
In this locked state, as the knock cover 28 is again knocked, the rib member 38 of the knock bar 22 rides on the narrow slope 45 formed at the body cylinder 1. Then, it falls into the deep groove 41 formed at the body cylinder 1, and caused to be in the unlocked state.
That is to say, each time the knock bar 22 is knocked, the above-mentioned locked state is switched to the unlocked state and vice-versa, which is repeated. In conjunction with this, the open/close mechanism for the writing lead feeding unit is opened and closed as already described.
Further, in the locked state, as shown in
Also in the second preferred embodiment as shown in
Therefore, as the knock cover is knocked one or two times, the lead fixing chuck 4 and the holder chuck 9 act to inch out the writing lead L, and the tip portion of the writing lead L is inched from the pipe end 7, thus allowing writing at once.
Thus, also in the first preferred embodiment as shown in
It should be noted that although the rotational drive mechanism is provided for rotating the writing lead according to writing in the above-described preferred embodiments, the present invention is not only applied to the mechanical pencil having the particular structure as described above, but also similar operational effects can be expected when the present invention is applied to the other mechanical pencils without the above-mentioned rotational drive mechanism for the writing lead.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-050574 | Mar 2012 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2013/054108 | 2/20/2013 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2013/133016 | 9/12/2013 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 7802936 | Izawa et al. | Sep 2010 | B1 |
| Number | Date | Country |
|---|---|---|
| 2264663 | Oct 1997 | CN |
| 57-174299 | Oct 1982 | JP |
| 58-151087 | Oct 1983 | JP |
| 1-132780 | Sep 1989 | JP |
| 2000-127673 | May 2000 | JP |
| 2002-200880 | Jul 2002 | JP |
| 2011-116028 | Jun 2011 | JP |
| Entry |
|---|
| International Search Report dated Apr. 23, 2013, issued in corresponding application No. PCT/JP2013/054108. |
| Office Action dated May 25, 2015, issued in counterpart Chinese patent application No. 201380012996.1 (6 pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20150023714 A1 | Jan 2015 | US |
