Note: Descriptions are shown in the official language in which they were submitted.
PROPELI.ING PENCIL
BAC_ _ OUND OF THE INVENTION
This invention relates to a knock-type propelling
pencil, and more specifically relates to such a propel-
ling pencil as prevents breaking of a lead by absorbing
resiliently the force to the lead when an excessive
pressure is applied to the leadO
A brief discussion of the prior art is provided below
with reference to Fig. 1 of the accompanying drawings.
For convenience, however, all of the drawings are first
explained, as follows.
BRIEF DFSCRIPTION OF THE DRAWINGS
Fig. 1 is a sectional view showing major portions of
a conventional propelling pencil provided with a protect
function free from breaking of a lead,
Fig. 2 is a vertical section view showing a propelling
pencil according to an embodiment of the present invention;
Fig. 3 is a vertical section view showing major
portions in Fig. 2;
Fig. 4A is a plan view showing a cushion sleeve of
Fig. 2;
Fig. 4B is a sectional view illustrated at 4-4 line
of Fig. 4A;
Fig. 5A, Fig. SA and Fig. 7A are plan views showing
other embodiments for the cushion sleeve;
Fig. 5B, Fig. 6B and Fig. 7B are sectional views
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illustrated respectively at 5-5 line, 6-6 line and 7-7
line corresponding to Fig. 5A, Fig. 6A and Fig. 7A;
Fig. 8A is a vertical section view showing another
embodiment of the cushion sleeve;
Fig. 8B is a side view showing the cushion sleeve of
Fig. 8A;
Fig. 9A is a plan view showing the last embodiment of
the cushion sleeve;
Fig. 9B is a side view showing the cushion sleeve of
Fig. 9A;
Fig. lOA is a plan view showing an outer cylinder
around a stopper hole;
Fig. lOB is a vertical section view on the basis of
Fig. lOA;
Fig. 11 is a vertical section view showing major
portions of the propelling pencil according to the other
embodiment of the present invention;
Fig. 12 is a vertical section view showing tip
portions of the propelling pencil according to still
another embodiment of the present invention,
Fig. 13 is an explosional cross-sight view showing
major portions of the propelling pencil according to
the last e~bodiment of the present invention; and
FigO 14 is a vertical section view showing major
portions in the assembled condition of the propelling
pencil in Fig. 13.
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DISCUSSION OF T~IE P:~IOR A~T
_ .
A conventional propelling pencil as shown in ~ig. 1
has heretofore been proposed, in which a protect function
free from breaking of a lead has been provided.
In Fig~ 1, reference numeral 1 is a holder,
reference numeral 2 is a lead sto:ring cylinder which is
inserted into the holder 1 slidably to the direction of the
axls, reference numeral 3 is a lead chuck fixed in the tip
of the lead storing cylinder 2, reference numeral ~ is a
chuck ring loosely fitted to the tip of the lead chuck 3.
Moreover, reference numeral 5 is a sleeve disposed between
aforesaid chuck ring 4 and aforesaid holder 1 and slidably
inserted into the aforesaid lead chuck 3, and in the rear
portion of the sleeve 5, a spring 7 is disposed between the
rear portion and the stopper 8 within the holder 1.
The spring 7 is effected in such a manner that the
break of a lead is prevented by way of absorbing motion of
the pressure to a lead, when the lead chuck 3 is appli.ed an
excessive pressure in the use of the pencil. The sleeve 5
is also provided with the another spring 6 to actuate -the
aforementioned lead storing cylinder 2 to put forward to the
return direction, and to be wound around the lead chuck 3.
Then, assuming that the knocked portion (not shown)
in the end of the lead storing cylinder 2 is pushed, the
lead storing cylinder 2 is moved to the front direction
against the actuating forc~ of the spring 6 to open the lead
chuck 3, and the lead lb projects out of the tip of the cap
la to be sent in the predetermined length. In the condition
of writing operation, if the excessive lead pressure is
added thereto, the sleeve 5 is moved backward through the
lead chuck 3 against the actuating force of the spring 7.
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Accordlng to this backward motion, the excessive lead
pressure is absorbed resiliently so -that the break of a
lead will be prevented.
However, since the construction requires the fact
that the sleeve 5 is forrned out of a me-tal pipe in which the
spring 7 is provided, there are some defects in such a
manner that the fact makes it difficult to manufacture and
assemble them and also causes the material cost to increase
into high cost.
SUMMARY OF THE INVENTION
The object of the present invention is to provide
a propelling pencil, in which the number of parts is
decreased and the efficiency for assembling works is risen
up so that the pencil can be produced at a reduced cost and
promises well-touching operation.
According to an aspect of this invention there is
provided a propelling pencil comprising: an outer cylinder
composed of a synthetic resin molded as a unitary structure
which will be gripped during the writing and which has at
least one engaging hole formed in the periphery on the front
side thereof; a resilient engaging member which has, on the
outer peripheral rear portion, at least one protrusion tha-t
engages with said engaging hole, and which has an inner
flange at the front end thereof; a lead chuck which is
slidably inserted in the engaging member, and which is
attached to an end of a lead pipe; a chuck-fastening tube
loosely fitted to a chuck portion at the end of the lead
chuck; and a spring which is disposed between said inner
rlange and one end of said lead pipe, and which so urges
the lead chuck that the chuck portion is squeezed by the
chuck-fastening tube.
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Other aspects of thix invention are disclosed in
our co-pending Canadian Patent Applica-tion Serial No,
410,839 filed on August 25, 1982, of which the present
application is a division.
PRE:E`ERRED EMBODIMENT OF THE INVENTION
Hereinafter there will be described in detail
embodiments of this invention by way of the accompanying
drawings.
Referring to Figs. 2 and 3, an outer cylinder 11
is molded up to a portion of tip fitting 12 as a unitary
structure. A guide portion 13 is fitted to the end of
the outer cylinder 11, and a lead pipe 14 is accommodated
in the outer cylinder 11 to slide in the axial direction.
A knock portion is detachably attached to the rear
end of the lead pipe 14, and a lead chuck 16 is fitted to
the other end of the lead pipe 14. The end of the lead
chuck 1~ penetrates through a hole formed in the center of
a chuck-fastening tube 17 which has a ]-shape in cross
section. The rear end of the chuck-fastening tube 17 is
brought into contact with the front end of a cushion
sleeve 19 which is slidable in the outer cylinder 11 in
the axial direction, and which is forwardly urged by a
spring ~resilient member) 18.,
The cushion sleeve 19 constitutes one of the
important elements of this invention, and is composed of
an elastic material which can be elastically deformed. As
shown in Figs. 3 and 4, furthermore, the cushion sleeve
19 consists of a sleeve portion 110 and a cushion por-tion
111 which is molded together with the sleeve portion 110
as a unitary structure, and which can be retractably
stretched in the axial direction. The cushion sleeve 19
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is secured to the outer cylinder 11 via its engaging
projection 112 which engages with a stopper hole lla in the
outer cylinder 11. Reference numeral 13a depic-ts a lead
guide made of rubber.
As shown in Figs. 3 and 4, furthermore, a slit llla
is formed in the cushion portion 111 of the cushion sleeve
19, so that the cushion portion 111 is deflected in -the
direction of diameter, and the engaging projec-tion 112 is
reliably engaged with the stopper hole llla in the outer
cylinder 11. Further, the cushion portion 111 has a
diameter greater than that of the sleeve portion 110. The
cushion portion 111 further has a hole lllb formed in the
circumferential direction so that it can be retractably
stretched in the axial direction. As will be mentioned
later, therefore, a second spring is not required to urge
the sleeve forward, enabling the assembling operation to
be greatly simplified, and the number of parts to be
reduced.
Figs. 5 to 9 illustrate the cushion sleeve 19
according to another embodiment in which the shape and
construction of the slit llla and hole lllb are modified
such that the cushion sleeve 19 reliably engages with the
stopper hole lla in the outer cylinder 11 and retractably
stretches in the axial direction. The engaging projection
112, slit llla, and hole lllb may be constructed in any
form provided the cushion portion 111 can be effectively
deformed.
The stopper hole lla for engagement with the
engaging projection 112 of the cushion sleeve lg is so
formed as to penetrate through -the peripheral wall of the
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outer cylinder 11 as shown in Figs. 2, 3 and 10. Further,
a sleeve guide groove 113 is formed in the inner wall of
the outer cylinder 11 along the axial direction as shown
in Fig. 10B. When the lead-propelling mechanism consisting
of lead pipe 4, lead chuc~ 16 and cushion sleeve 19, is to
be incorporated from the rear end of the outer cylinder 11,
the sleeve guide groove 113 works to reliably bring the
engaging projection 112 into engagement with the stopper
hole lla formed in the outer cylinder 11. For this purpose,
the sleeve guide groove 113 stretches from the stopper hole
lla to the rear end of the outer cylinder 11. Here, however,
the sleeve guide groove 113 may be formed only in the
vicinity of the stopper hole lla to fully exhibit its
function for guiding the engaging projection 112.
Opera-tion of the invention and the order of
assembling will be mentioned belowr
First, the cushion sleeve 19 and the cushion
portion 111 have been formed as a unitary struc-ture.
Therefore, the lead-propelling mechanism can be inserted
into the outer cylinder enabling the operation efficiency
to be enhanced. Further, since the second spring is not
required to absorb excessive writing pressure, the number
of parts can be reduced, and the pencil can be cheaply
manufactured.
Further, since the lead-propelling mechanism is
inserted from the rear end of the outer cylinder 11, it
is permitted to mold -the outer cylinder 11 as a unitary
structure up to the portion of tip fitting 12 thereof.
Accordingly, the operation efficiency can be increased,
the number of parts can be reduced, and the manufacturing
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cost can be reduced. As required, furthermore, the outer
cylinder 11 can be formed as a unitary structure up to -the
guide portion 13. In this case, the operation efEiciency
can be further increased -to reduce the manufacturing cost.
In carrying out the assembling operation, the
engaging projection 112 of the cushion sleeve is reliably
and simply brought into engagement with the stopper hole lla
of the outer cylinder 11 since the sleeve guide groove 113
has been formed in the inner wall of the outer cylinder 11.
Owing to this engagement, furthermore, position of the
cushion sleeve 19 is not deviated.
In the propelling pencil which is completely
assembled as mentioned above, not only the spring 18 for
knocking but also the cushion portion 111 having a small
modulus of elasticity work to absorb excessive writing
pressure, the cushion portion 111 of the cushion sleeve 19
contracts as indicated by a dotted line in Fig. 3 in case
an excessively great writing pressure is exerted on the
lead 114. That is, the lead 114 retracts into the outer
cylinder 11, and is no-t broken.
Fig. 11 shows an engaging portion of the engaging
projection 112 according to another embodiment of this
invention, in which the engaging projection 112 of the
cushion sleeve 19 is brought into engagement with a stepped
portion llb in the inner wall instead of the s-topper hole
lla.
This embodiment exhibits the same effects as those
of the above-mentioned embodiment. In this embodiment,
however, the outer cylinder 11 can be produced more simply
since there is no need of forming the stopper hole lla and
the sleeve guide groove 113.
In the case of this embodiment, however, it is
desired that the tip fitting 12 ana the guide portion 13 of
Fig. 2 are formed separately from the outer cylinder 11.
According to this invention as mentioned above, the
sleeve has a spring function for absorbing excessively great
writing pressure. Furthermore, the assembling efficiency
can be increased strikingly, and -the number of par-ts can be
reduced to remarkably decrease the manufacturing cost.
Fig. 12 is a vertical section view showing tip
portions of the propelling pencil according to s-till another
embodiment of this invention. As compared with the propelling
pencil of the embodiment in Fig. 2, that of Fig. 12 is
provided with an outer cylinder 11 united with the tip
fitting 13' and a lead guide portion 13a'.
This structure makes it easier to automatically
assemble the propelling pencils.
Figs. 13 and 14 are a perspective view showing a
knock-type propelling pencil according to the o-ther
embodiment of this invention in a disassembled manner, and a
section view illustrating major portions thereof, in which
reference numeral 21 denotes an outer cylinder composed of a
synthetic resin of a good quality, which is molded as a
unitary structure and which will be gripped by a person who
writes. The outer cylinder 21 has a core guide hole 21a in
a tip portion thereof and an engaging hole 21b in the outer
peripheral portion thereoE.
In the outer cylinder 21 is placed a cup-shaped
resilient engaging member 22 whlch has, on the peripheral
rear end portion thereof, a tapered protrusion 22b that
engages with said engaging hole 21b, and an inner flange 22a
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at an end portion thereof. In the engaging member 22 is
slidably inserted a lead pipe 23. A chuck-fastening tube
25 has been fitted to a chuck portion 24a at the end of a
lead chuck 24 that is attached to an end 23a of -the lead
pipe 23.
A spring 26 is interposed between the inner flange
22a and -the end 23a of the lead pipe 23, and so urges the
lead chuck 24 that the chuck portion 24a is squeezed by the
chuck-fastening tube 25.
Further, the engaging member 22 and the lead chuck
24 may be assembled together as a unitary structure, the
lead chuck 24 being provided with a lead pipe 23 with a
chuck-fastening tube 25 being fitted thereto via a spring.
The above assembly is inserted in the ou-ter cylinder
21 from -the side of the rear end overcoming the resilient
force of the tapered protrusion 22b which will then engage
with the engaging hole 2lb.
According to this invention as mentioned above,
the assembly is incorporated into -the outer cylinder 21 by
2~ simply driving it from the rear side in such a manner that
the tapered protrusion 22b will engage with the engaging
hole 21b. To disassemble the device, the tapered protrusion
22b protruded through the engaging hole 21b should simply
be pushed by a pin or the like, and the assembly should be
pulled rearwards.
The lead in the knock-type propelliag pencil can
be propelled in the same manner as the conventional
propelling operation. That is, the engaging member 22 has
been detachably attached to the outer cylinder 21.
Therefore, when the lead pipe 23 is knocked from the rear
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direc-tion, the lead chuck 24 holding -the lead is pushed
forward to liberate the chuck-fastening tube 25 which is
fitted to the chuck 24a, whereby the lead is ]iberated.
When the knocking operation is discontinued, the spring 26
so urges the lead chuck 24 that the core is held again. By
repeating this operation, the lead is propelled through the
lead guide hole 21a.
In the above-mentioned embodiment, a tapered
protrusion which works as a resilient piece is formed on the
outer periphery of the cup-shaped engaging member 22. The
tapered protrusions, however, may be provided in a plurality
of numbers at symmetrical positions on the outer periphery.
When a plurality of tapered projections are
provided as mentioned above, a plurality of engaging holes
should be formed in the outer cylinder 1 correspondingly.
Further, as a modified example of the engaging member, a
plurality of slits may be formed in the outer peripheral
portion of the cup-shaped engaging member to impart
resiliency, and the tapered protrusions may be formed at
the outer peripheral rear ends.
According to the knock-type propelling pencil of
this invention as mentioned above, the outer cylinder is
composed of a synthetic resin ~hich can be easily molded as
a unitary structure, and the engaging member incorporating
the chuck device whlch includes a lead-propelling mechanism,
is detachably inserted into the outer cylinder from the rear
side thereof. ~herefore, the pencil can be simply
constructed, and manufactured at a reduced cost. In order
to further reduce the number of parts, the chuck-fastening
tube and the engaging member may be molded as a unitary
structure.
