U.S. patent number 3,637,316 [Application Number 05/041,666] was granted by the patent office on 1972-01-25 for writing tool.
Invention is credited to Helmut Bross.
United States Patent |
3,637,316 |
Bross |
January 25, 1972 |
WRITING TOOL
Abstract
A writing instrument having a mechanism for advancing and
retracting the writing member, e.g. a cartridge disposed in the
housing of the writing instrument, and a clip provided laterally on
the housing to secure the writing instrument to a pocket. The
mechanism is so constructed that the retraction of the writing
member can be effected optionally by actuating a pushbutton
provided on the rear end of the housing or by lifting the clip in
relation to the longitudinal axis of the housing.
Inventors: |
Bross; Helmut (Altenberg near
Nuremberg, DT) |
Family
ID: |
21917700 |
Appl.
No.: |
05/041,666 |
Filed: |
May 21, 1970 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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758829 |
Sep 10, 1968 |
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Foreign Application Priority Data
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Sep 12, 1967 [DT] |
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P 15 61 807.2 |
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Current U.S.
Class: |
401/104; 401/198;
401/107 |
Current CPC
Class: |
B43K
24/08 (20130101) |
Current International
Class: |
B43K
24/08 (20060101); B43K 24/00 (20060101); B43k
005/16 () |
Field of
Search: |
;401/198,199,104-116 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Charles; Lawrence
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of application Ser. No. 758,829,
filed Sept. 10th, 1968 by Helmut Bross, and now abandoned.
Claims
I claim:
1. A writing instrument comprising, in combination:
a. a hollow housing elongated along an axis of the elongation and
having a forward and a rear end, each end defining an opening;
b. an elongated writing member having two opposite ends and a
writing point at one of the ends, and arranged within said housing
along the axis of elongation thereof, with said writing point
adjacent the forward end of said housing;
c. a spring means arranged within said housing for biasing said
writing member toward the rear end of said housing;
d. an operating means arranged in contact with said writing member
at the other of the ends of said writing member for displacing said
writing member along the axis of said housing between a retracted
position having said writing point entirely within said housing and
an advance position wherein said writing point extends out of said
housing against the bias of said spring means by applying a force
parallel to the axis of said housing to said operating member in
the direction of the forward end of said housing;
e. a securing clip having a free end and arranged outside of and
adjacent to said housing near the rear end thereof;
f. means including a locking element formed on said securing clip
adjacent the forward end thereof for retaining said writing member
in the advanced position and operable to release said writing
member and permit it to move to its retracted position both when a
force parallel to the axis of said housing is applied to said
operating member in the direction of the forward end of said
housing and, separately, when the free end of said securing clip is
biased away from said housing in a direction that is substantially
perpendicular to the axis of said housing; and
g. means separate from said retaining means and coacting with said
operating means for retaining said writing member in the retracted
position after said securing clip is biased away from said
housing.
2. The writing instrument as defined in claim 1, further including
a connecting portion connecting said operating means to said
securing clip adjacent the rear end of said securing clip, an
axially extending slot in said housing receiving said connecting
member and effective to prevent rotation of the operating means,
and guide surfaces and stops for said locking element formed on the
outside of the housing and cooperating with said locking element to
form said advanced position retaining means.
3. A writing instrument as defined in claim 2, further including a
resiliently outwardly urged pawl formed on said operating means,
and a recess in said housing, said pawl engaging said recess in the
retracted position of the writing member to form said separate
retaining means.
4. A writing instrument as defined in claim 3, wherein a portion of
said securing clip extends forwardly of said locking element and
slopes outwardly from the housing to facilitate the introduction of
the material of a pocket between said securing clip and said
housing.
5. A writing instrument as defined in claim 2, wherein there is
formed on the exterior of said housing:
a. a rearmost, a central, and a foremost inclined guide surface,
axially spaced from one another, against which said locking element
bears, and all inclined in the same sense with respect to the axis
of elongation of said housing;
b. a stop surface at the rear end of said central guide surface
which is effective to engage said locking element when the writing
member is in its advanced position;
c. a transfer guide surface between each of said three axially
spaced guide surfaces; and
d. a further stop surface arranged to be effective on movement of
the locking element from said rearmost guide surface to said
central guide surface to prevent said locking element from being
deflected as far as the respective one of said transfer guide
surfaces connecting said foremost guide surface to said rearmost
guide surface, so as to skip the stop surface formed on the end of
the central guide surface.
6. A writing instrument as defined in claim 2 wherein there is
formed on the outside of said housing:
a. a rearmost, a central and a foremost inclined guide surface,
which are axially spaced from one another and against which said
locking element bears, the inclination of the rearmost guide
surface to the axis of elongation of said housing being opposite to
that of the central and foremost guide surface;
b. a stop surface at the rear end of said central guide surface
arranged to be effective to engage said locking element when said
writing member is in its advanced position;
c. a transfer guide surface between each of said three axially
spaced guide surfaces; and
d. a further stop surface arranged to be effective on movement of
said locking element from said central guide surface to said
foremost guide surface to prevent said locking element from being
deflected in the direction of said transfer surface from said
rearmost guide surface to said central guide surface.
7. A writing instrument as defined in claim 1, further comprising a
member which is displaceable rearwardly under the action of said
spring means, said member having stops and guide surfaces formed
thereon, and the locking element associated with said securing clip
being a locking pawl, said locking pawl engaging said member to
prevent movement thereof to the retracted position.
8. A writing instrument as defined in claim 7, wherein said locking
pawl comprises an extension of said securing clip, and wherein said
housing has a wall and defines an aperture in said wall, through
which said extension passes to engage said member.
9. A writing instrument as defined in claim 7, wherein said locking
pawl has a tongue in the form of an incision in said housing, said
tongue being raised from said member when said securing clip is
biased away from said housing.
10. A writing instrument as defined in claim 7, further including
an annular extension on that portion of said operating means which
extends into said housing to form a limiting stop for said member
when said member is shifted rearwardly.
11. A writing instrument as defined in claim 1 wherein said
securing clip is connected to said operating means and said
operating means is adapted to swivel about an axis perpendicular to
the axis of said housing when said securing clip is lifted, and
further comprising two outwardly urged, radially resilient pawls on
said operating means, and stops and guide surfaces on the interior
of said housing, said stops and guide surfaces cooperating with one
of said pawls to form said retaining means for the advanced
position, and a recess in said housing cooperating with said two
pawls upon the biasing away of said securing clip, said one of said
pawls being so arranged that on the biasing of said securing clip
it disengages from one of said stops which arrest said writing
member in its advanced position.
12. A writing instrument as defined in claim 1 wherein said writing
member comprises a bundle of fibers enclosed in a tube having an
outer diameter, and said housing has an inner diameter
substantially larger than said outer diameter and defined by a wall
and is provided with a guide means for said tube at the forward end
of said housing, which guide means is axially spaced from the
opening defined in the forward end and is effective for guiding
said tube in said opening when said writing member is in its
advanced position, and is located at such a distance from said
housing wall for assuring that no writing ink can contact said
housing under the influence of capillary action in the gap between
said tube and said housing.
Description
BACKGROUND OF THE INVENTION
The present invention relates to writing instruments such as
ballpoint or felt pens.
Writing instruments are known which comprise an operating member
axially displaceably mounted on the rear end of the housing of the
instrument and adapted to be operated by finger pressure, and a
writing member, for example, a cartridge disposed in the housing,
displaceable under or against the action of a spring. The spring
tends to move the writing member from a forwardly shifted position
in which the writing point of the writing member projects out of
the forward end of the housing, and a retracted position in which
the writing point is concealed by the housing, the said member
being securable in these positions. In many cases, a shifting
mechanism is provided which comprises a locking element which is
adapted to be pushed, under the pressure of the actuating member or
of the spring, against guide surfaces formed on a shifting member,
on which guide surfaces the locking element is moved transversely
in relation to the longitudinal axis of the housing and is thus
brought into the region of stops provided on the shifting member
and is caused to bear against the stops, the bearing of the locking
member against one of the stops fixing the writing medium holder in
one of the two positions.
More especially in writing instruments in which the writing point
is fed with ink, e.g., in the felt pens which have recently become
increasingly widely employed, and in which the writing member is
formed of a bundle of fibers, it is found desirable to provide
means to ensure that the writing instrument is not put into the
pocket with the writing point projecting from the housing, which
would result in very undesirable soiling of the clothing. A known
safety measure of this type, in cases where there is provided on
the outside of the housing of the writing instrument a securing
clip which can be bent over so as to increase the distance between
it and the housing wall and so as to set up a substantially
resilient return force, consists in so designing the arrangement
that, as a result of the positive bending-over of the clip when it
is pushed on to the wall of a pocket, the cartridge is
automatically released from its forwardly pushed position and
thereby brought into its retracted position under the action of the
compression spring. In the known writing instruments of this kind,
the disadvantage exists that the cartridge can only be brought out
of the forwardly pushed position into the retracted position by
bending-over of the clip. Therefore, the clip must also be actuated
when the user of the writing instrument wishes to bring the
cartridge into its retracted position before pushing the clip on to
the wall of a pocket. The movement of the cartridge from the
retracted position into the forwardly pushed position in the known
writing instruments takes place by depression of an operating
member provided on the rear end of the housing. It is troublesome
for the user to manipulate the shifting mechanism differently
depending upon the position in which the cartridge is situated, and
this substantially impairs the usefulness of such a writing
instrument.
SUMMARY OF THE INVENTION
According to the present invention there is provided a writing
instrument comprising a housing, an operating member axially
displaceably mounted in the rear of the housing, for displacement
by finger pressure, a spring mounted within said housing, a writing
member within said housing and having a writing point adjacent the
forward end of said housing and axially movable rearwardly under
the action of said spring to a retracted position, in which the
writing point is within the housing, and axially movable by said
operating member to a forward position in which the point projects
from the forward end of the housing, locking means releasably
locking the writing member in the forward position, stops to arrest
the writing member in the forward and retracted positions, a
securing clip externally of the housing, and means associated with
the operating member and with the securing clip to release the
locking means either by depressing the operating member or by
lifting the clip away from the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is an elevational view, mostly in section, of one
embodiment of writing instrument according to the invention, in the
form of a felt pen, with the cartridge in the retracted
position;
FIG. 1b is an enlarged longitudinal section through the writing end
of the felt pen of FIG. 1;
FIG. 2 illustrates the writing instrument shown in FIG. 1, with the
cartridge in the forwardly shifted position;
FIG. 3a is an enlarged longitudinal section through the writing end
of a felt pen according to the invention, wherein the means for
preventing soiling of the inside wall of the housing, lying in the
region of the forward aperture of the housing, is modified as
compared with the embodiment illustrated in FIGS. 1 and 2;
FIG. 3b is a front view of cap according to the present
invention;
FIG. 4 is an enlarged plan view of the outside of a housing part of
a writing instrument according to the invention, wherein the guide
surfaces and stops cooperating with the locking member are formed
on the outside of the housing;
FIG. 5 is a side view of the lower end of a securing clip on which
there is provided a locking element which cooperates with guide
surfaces and stops provided on the outside of the housing;
FIG. 6 is an illustration corresponding to FIG. 4, but drawn to a
smaller scale, of an embodiment in which the guide surfaces and
stops formed on the outside of the housing are differently arranged
from those of FIG. 4;
FIG. 7 is a longitudinal section through the rear end of a writing
instrument according to the invention, wherein the securing clip is
connected to a pushbutton adapted to be swivelled when it is lifted
in the housing, the cartridge here being situated in the retracted
position;
FIG. 8 illustrates the embodiment illustrated in FIG. 7 with an
arrangement of the parts associated with the shifting mechanism
which corresponds to the forwardly pushed position of the
cartridge;
FIGS. 9 and 10 are longitudinal sections through the rear end of
two embodiments of the invention, wherein the stops and guide
surfaces for the locking member are provided on a part situated
within the housing and axially displaceable therein;
FIG. 11 is a longitudinal section through the rear end of an
embodiment in which the stops and guide surfaces for the locking
member are again formed on a part displaceable within the housing,
the locking member being provided on a securing clip;
FIG. 12 is a view of a shifting mechanism corresponding to FIG. 11,
wherein the stops and guide surfaces for the locking member are of
different construction;
FIG. 13 is a longitudinal section through the rear end of a further
embodiment, wherein the abutments and guide surfaces for the
locking member are again provided on a part axially displaceable in
the housing, the locking member being formed in this case on a
tongue formed by an incision in the housing wall; and
FIG. 14 is a plan view of FIG. 13 as seen in the direction of the
arrow A.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Parts having corresponding functions are denoted by the same
reference numerals in the various figures. The terms "lower" and
"upper" are used to denote those portions nearer to, and further
away from the writing end of the instrument respectively.
In the figures, the housing 1 of the writing instrument, which is
constructed either in one piece or in a number of parts, has
axially slidable therein a writing member or cartridge 2. A
pushbutton 3 mounted on the rear end of the housing is also axially
displaceable in the latter, to move the cartridge 2 forward against
the action of a compression spring 4 disposed in the forward part
of the housing and bearing at one end against the cartridge 2 and
at its other end against a projection on the inside of the housing.
Near to its rear end the housing is provided with a securing clip
5. In each of the embodiments the cartridge 2 may be releasably
locked in the forward position by a locking member.
In the embodiments illustrated in FIGS. 1a, 1b, 2, 4, 5 and 6 the
locking member is constructed as an extension 6 projecting from
that side of the clip 5 which is closer to the housing 1. The clip
5 consists of a bent-over portion, at its upper end extending away
from the housing 1, a central portion substantially parallel to the
housing and a portion 5' at its lower end which slopes away from
the housing to facilitate the introduction of the material 7 of a
pocket wall between the locking member 6 and the housing 1.
The stops and guide surfaces for the locking member may be
positioned and formed on the outside of the housing as illustrated
in FIGS. 4 and 6. In the embodiment according to FIG. 4, the
housing is polygonal and a group of three guide surfaces are
disposed at different distances from the longitudinal axis of the
housing and inclined in the same direction. The uppermost and
central guide surfaces 8 and 9 respectively are formed on a
projection 11 of the housing, while the lowermost guide surface 10
is created by a step descending from a surface 14 to a surface 12
which is at a shorter distance from the longitudinal axis of the
housing than the surface 14. At that end of the central guide
surface 9 which is closer to the pushbutton 3, a stop for the
locking member which becomes operative when the cartridge is in the
forwardly pushed position, is formed by a stop surface 13 extending
parallel to the longitudinal axis of the housing and also formed on
the projection 11.
In the embodiment according to FIGS. 1a, 1b and 2, a special stop
for the locking member 6 when the cartridge is in the retracted
position is not required, because the latter is held in the
retracted position by the same stop which becomes operative on
lifting of the securing clip and which will hereinafter be
described. The stop surface 13 performs a further function, in
that, when the locking member 6 passes from the uppermost guide
surface 8 to the central guide surface 9, it prevents the locking
member from being deflected as far as the surface 15 of the
transfer region from the lowermost guide surface 10 to the
uppermost surface 8, and skipping the position in which the
pushed-forward cartridge is arrested. As will readily be seen, such
a deflection would result in errors in the shifting movement. The
surface 15 of the transfer region rises up to the level of a
surface 16, which descends in one step to a surface 17 which is
consequently at a shorter distance from the housing axis than the
surface 16. It will be understood that this step forms a boundary
of the uppermost guide surface 8. The surface 17 is also closer to
the longitudinal axis of the housing than the surface 14, the two
levels being joined by a sloping surface 18 which rises from the
surface 17. Also provided for the locking member is a stop surface
19 on a strip-form projection 20 formed on the housing, and a
further stop surface 21 formed by a step situated at the lower end
of the surface 12 and rising therefrom, these stop surfaces sloping
in the same direction as the guide surfaces 8 to 10.
When the pushbutton 3 is actuated, the path described by the
locking member 6, shown in phantom in FIG. 4, is illustrated by a
dash-dotted arrowed line. When the pushbutton 3 is depressed from
the retracted position, the locking member is first pushed against
the guide edge 8 and is thus first deflected transversely in
relation to the longitudinal axis of the housing. As soon as the
locking member has left the operative range of the guide surface 8,
it slides along a longitudinal guide surface 22 formed on the
projection 11. As soon as the locking member has left the guide
surface 22, it abuts the stop 19 and springs back about the axis of
the holder, and enters the operative region of the central guide
surface 9, on which it slides until it encounters the surface 13.
The pushbutton 3 and, thus, also the cartridge 2, is thereby
arrested in its forwardly pushed position (see FIG. 2). The
deflection of the locking member after it has slid off the guide
surface 22 in the direction of the central guide surface 9 takes
place under the action of the resilient return force which has been
produced in the clip 5 by the preceding lateral deflection in the
course of the pressure of the locking member 6 against the guide
surface 8. As soon as the locking member 6 has entered the
operative region of the guide surface 9, it is pressed against the
guide surface 9 by the pressure exerted on the cartridge by the
spring 4 and transmitted through the pushbutton 3 and the securing
clip 5, so that the locking member can slide along this surface
until it encounters the surface 13.
When the pushbutton 3 is pushed downwards from its forwardly pushed
position (FIG. 2) the locking member 6 falls on to the surface 12
and, on release of the pushbutton, abuts the guide surface 10 owing
to the pressure of the spring 4, and slides along the said guide
surface 10 under the further pressure of the spring 4. As soon as
the locking member 6 has left the guide surface 10, it slides along
the longitudinal guide surface 23 on the projection 11 and finally
returns into its initial position, which corresponds to the
retracted position of the pushbutton and thus also of the
cartridge. The bearing of the working surfaces of the locking
member 6, which is of rhomboidal form as seen in plan view, on the
guide surfaces 8 to 10 is also ensured by a resilient return force
which acts on the clip 5 to push the clip and thus also the locking
member 6 in the direction of the housing wall. The clip 5
consequently forms a rocking arm which can be radially and
transversely deflected in relation to the longitudinal axis of the
housing against a resilient return force, the deflectability being
promoted by virtue of the fact that the web which connects the
securing clip to the pushbutton has a region 5" of reduced
thickness. With regard to the stop surfaces 19, 21, it is also to
be noted that they limit the forward displacement of the locking
member and thus also of the pushbutton from the retracted rest
position or from the advanced rest position. In the embodiment
illustrated in FIGS. 1 and 2, there is formed on the pushbutton 3 a
further rocking arm 24 which lies within the housing 1 and can be
bent over towards the longitudinal axis of the housing against the
action of a resilient return force. Situated on the free end of the
rocking arm is a pawl 25 which, when the cartridge is in the
forwardly pushed position, is pressed against the inside wall of
the housing 1 owing to the aforesaid resilient return force (FIG.
2). When the clip 5 is lifted, for example, due to the fact that
the writing instrument is pushed on to the wall 7 of a pocket (see
FIG. 1), the arresting member 6 becomes disengaged from the stop by
which it is fast in its forwardly pushed position. The cartridge
and the pushbutton 3 are then shifted backwards until the pawl 25
engages, in the course of this displacement, in a recess 26 formed
in the longitudinal path of movement of the pawl on the housing.
The cartridge, and thus also the pushbutton, is arrested in its
retracted position.
In the embodiment illustrated in FIGS. 1a, 1b and 2, the pushbutton
3 is countersunk in the housing 1, so that it can be actuated by
axial pressure exerted on a roughened surface 5'" on the upper end
of the clip 5. The web 5", by which the clip is connected to the
pushbutton, is guided along in a slot 27, whereby the pushbutton is
secured against rotation.
It will be seen from the foregoing description that the transfer of
the cartridge from the position according to FIG. 2 into the
position according to FIG. 1 may be effected optionally by exerting
an axial pressure on the pushbutton or by lifting the clip 5 from
the housing 1.
The formation of the guide and stop surfaces for the locking member
on the outside of the housing affords the advantage that the
housing, which is preferably injection-molded from plastics, can
readily be formed. The pushbutton 3, the clip 5 and the rocking arm
24 may also be formed as an integrally formed plastics part.
Instead of the guide and bearing surfaces being formed as
illustrated in FIG. 4, these surfaces may be formed as illustrated
in FIG. 6 in which the housing is circular in section. In
contradistinction to the arrangement according to FIG. 4, the guide
surfaces 28, 9 and 10 situated one above the other in the
arrangement according to FIG. 6 are not all inclined in the same
direction. The slope of the uppermost guide surface 28 is in this
case opposite to the slope of the other two guide surfaces 9, 10,
which are inclined in the same direction. In other respects, there
is no basic difference between the arrangements illustrated in
FIGS. 4 and 6. The manner of operation of the arrangement
illustrated in FIG. 6 will be readily apparent from the dash-dotted
path of movement of the locking member. In this case a stop surface
29 is provided, which, on the transfer of the locking member from
the central guide surface to the lowermost guide surface, prevents
the locking member from being deflected towards the region of
transfer from the uppermost guide surface to the central guide
surface.
In the embodiment of FIGS. 7 and 8, the clip is connected to a
pushbutton 3' which is adapted to swivel in the housing 1 when the
clip is lifted from the latter. The swivelling takes place about an
axis which is at a right angle to the longitudinal axis of the
housing. Two rocking arms 24, 30 are formed on the lower end of the
pushbutton 3'. The rocking arm 24 is comparable in its function to
the rocking arm 24 in the embodiment according to FIGS. 1 and 2; it
consequently also comprises a locking pawl 25 which is adapted to
engage in an aperture 26 in the housing wall 1. As with the clip 5
of FIGS. 1 and 2, there is formed on the free end of the other
rocking arm 30 a locking member 6' which cooperates with guide
surfaces and stops which in this case are formed on the inside of
the housing. The stops situated one above the other in relation to
the longitudinal axis of the housing are denoted by 31 and 32. The
stops 31 here serves to arrest the locking member when the
cartridge is in the forwardly pushed position (FIG. 8), while the
locking member 6' is adapted to engage against the stop 32 when the
cartridge is in the retracted position. In the position illustrated
in FIG. 7, the cartridge is situated in the retracted position, but
the stop 32 is here not operative, since the return of the
cartridge from the forwardly pushed position has been effected, not
by depression of the pushbutton 3', but by lifting of the clip 5.
In this instance, the stop formed by the wall of the aperture 26
provided in the housing for the locking pawl 25 takes effect, which
stop can become operative independently of the stop 32 of the
actual shifting mechanism. When the securing clip 5 is lifted from
the housing 1, the locking member 6' is disengaged from the guide
surfaces and stops of the shifting mechanism due to the fact that
the pushbutton 3' is swivelled within the housing 1 as a result of
the lifting action, which is clearly apparent on comparison of FIG.
8 with FIG. 7. Also provided on the pushbutton 3' is an extension
33 which projects from the lower end thereof and which acts as a
push member for the cartridge. It is advantageous for a reliable
operation of the embodiment illustrated in FIG. 7 and 8 for the
clip 5 to be substantially rigidly constructed, so that radial
deflection of the clip in relation to the longitudinal axis of the
housing immediately results in swivelling of the pushbutton.
The embodiments illustrated in FIGS. 9 and 10 have in common the
feature that the stops and guide surfaces for the locking member
are provided on known forms of component 34 axially movable within
the housing, under the action of the spring 4, from a forward
position in which the cartridge is situated in its forwardly pushed
position, into a rear position in which the cartridge is situated
in its retracted position. FIGS. 9 and 10 illustrate the forwardly
pushed position. The clip 5, which is separate from the pushbutton
3", is so held in the region of its upper end on the housing 1 as
to be capable of springing in a radial direction, comprises a
locking pawl 25 which extends through an aperture 26 in the housing
wall and by means of which the component part 34 can be arrested in
its forward position.
In the embodiment illustrated in FIG. 9, the outside surface of the
component 34 is for this purpose formed with an annular slot 35 in
which the locking pawl 25 can engage. Only when the clip is lifted
from the slot 35 by introduction of material 7 between the clip and
the housing wall can the component 34 shift into the retracted
position, the shifting movement stopping as soon as the upper end
of the component 34 encounters the flange 36 on the pushbutton 3",
which in turn bears against an inwardly projecting shoulder 37 of
the housing 1. The action of this stop is again independent of the
stop formed on the inside of the component 34 for the retracted
position of the locking member 6". On the inside surface of the
component 34 are formed the guide surfaces for the locking member
and the stop for its forward position. The stops are situated at
the ends of slots which extend to alternate distances towards the
rear, the guide surfaces being formed on the forward end of the
webs remaining between the slots. Rotational movement of the
locking member is brought about by virtue of the fact that, on
depression of the pushbutton, sloped flanks on outwardly radially
extending projections 38' of a driving member 38 are pushed against
sloped flanks of the radially extending projections 6a of the
locking member 6". The Projections are brought into the effective
range of the guide surfaces which slope in are brought into the
effective range of the guide surfaces which slope in relation to
the longitudinal axis of the housing, from which they slide either
into the short slots or into the long slots, depending upon whether
the pushbutton has been actuated with the cartridge in the
retracted position or in the forwardly pushed position. The
projections 38' of the driving member 38 are longitudinally
displaceable in the said slots.
In FIG. 10 the guide surfaces and stops are formed on a
heart-shaped cam 39 on the outside of the component 34. In this
case, the locking member consists of a ball 6"' which engages in
one case in the heart-shaped cam 39 and in the other case in a
circular slot 41 formed in the inner surface of a part 40 which is
also axially displaceable in the housing 1. Since this mechanism is
known per se, its operation need not be described in detail. When
the cartridge is pushed forwards, the locking pawl 25 of the
securing clip 5 cooperates with a flange 42 on the part 40, which
is pressed under the action of the spring 4 against the locking
pawl 25, as is apparent from FIG. 10. When the locking pawl is
withdrawn from the flange 42, the parts 34 and 40 are shifted to
the rear until the flange 42 on the part 40 encounters the inwardly
turned-over edge 43 of a sleeve 44 screwed into the housing 1.
The embodiment illustrated in FIG. 11 differs from that according
to FIG. 10 substantially in that the locking member 25' engaging
the heart-shaped cam 39 is formed on the securing clip 5. The stop
which acts independently of the stops for the locking member 6
which are formed on the heart-shaped cam 39 is formed by the
inwardly projecting shoulder 45 of the housing 1, against which
shoulder the part 34 formed with the cam bears in the course of its
displacement when the locking member 6 is lifted out of the
heart-shaped cam 39. In the embodiments illustrated in FIGS. 10 and
11, the part 34 is integrally connected to the pushbutton 3".
Instead of the heart-shaped cam in the embodiment according to FIG.
11, there may be provided on the outside of the component 34 guide
surfaces and stops for the locking member 6, which are formed as
shown in FIG. 12. Such a construction is known in principle, so
that it need not be further discussed. In the constructions of
FIGS. 9 to 12, the locking member is normally held in engagement
with the guide surfaces and stops by means of the clip pressed
against the housing under the action of a resilient return force.
This engagement is broken only when a material is introduced
between the clip and the housing.
The embodiment illustrated in FIGS. 13 and 14 is distinguished from
those illustrated in FIGS. 9 to 12 by the fact that the locking
member is formed on a tongue which is formed by an incision 46 in
the housing wall and which is radially movable in relation to the
longitudinal axis of the housing against the action of a resilient
return force, and to which the clip 5 is so connected that, when it
is lifted, the locking member 25' becomes disengaged from the stop
which arrests the cartridge in its forwardly pushed position, and
which in this case is again formed on the heart-shaped cam 39 on
the outside of the axially displaceable component 34.
FIGS. 1a to 3b also illustrate the safety measures with which the
invention is additionally concerned, for preventing the housing
wall which lies in the region of the forward housing aperture 48
from being soiled with writing medium. For this purpose, it is
proposed in accordance with the invention, in a writing instrument
comprising a writing member constructed as a bundle of fibers 49
and enclosed in a narrow tube 50, to provide in the forward end of
the housing, at a distance from the housing aperture 43, a guide
for the enclosure tube, which holds the latter at the housing
aperture, when the cartridge is in the forwardly pushed position,
at such a distance from the housing wall that no writing liquid can
be drawn into the gap "a" between the tube 50 and the housing 1 by
capillary action. In the illustrated embodiment, the guide is
formed by extensions 51 projecting from the inside of the housing
slightly behind the aperture 48.
It is furthermore proposed to provide behind the guide 51, in
spaced relationship thereto, a cup-shaped cap 52 (see FIG. 1b)
which masks the writing member 49 from the housing aperture in the
retracted position and which is adapted to be expanded against the
action of the resilient return force when the writing member is
pressed against the base of the cup, and which is adapted to close
automatically under the action of the return force when the writing
member is retracted from the expanded opening. The angle which the
wall portions of the cap 52 which directly bound the expansible
opening of the base of the cup enclose with the longitudinal axis
of the housing should be of such size that, even after the
expansion of the cap, they are at such a distance "b" from the
housing wall that the writing liquid which wets the edges of the
expansible aperture cannot be drawn by capillary action into the
space between the wall portions of the cup and the housing wall
extending between the latter and the forward housing aperture. The
base of the cup which forms the cap 52 has, as is apparent from
FIGS. 1a to 3b, the form of a cone whose aperture or open angle is
greater than 90.degree.. In the embodiment illustrated in FIGS. 1a
and 2, the cap 52 may be formed of a cup-shaped part consisting of
rubber, the edge of the aperture of which is outwardly turned over
and gripped between the spring 4 and a housing shoulder. The
expansible aperture is in this case formed by one or more incisions
in the base of the cap.
If the cap consists of an injection-molded plastic part having
relatively low elasticity, as in the embodiment according to FIG.
3a, and equal slots 53 (see FIG. 3b) are formed in the production
of the cap 52' it is found necessary to take particular steps to
cause those edges of the flaps of the cap which bound the slots to
bear one against the other when the cartridge is in the retracted
position. This can be done by means of a sleeve 54 consisting of
highly elastic material, for example rubber, which is stretched
over the cap so that it is expanded, the sleeve being formed with
an aperture 55 in its base. Owing to the return force produced in
the sleeve 54 by the expansion, the flaps of the cap 52 are applied
one against the other as soon as the cartridge is retracted into
its rear position.
In order to avoid damage to the writing member constructed as a
bundle of fibers, it is found desirable to round off the inside
edge 53' of the expansible cap.
* * * * *