Side knock-type ball point pen

A side knock-type ball point pen includes a barrel having a front end portion and a rear end portion, a refill-receiver member axially movably incorporated within the barrel, a refill removably received in the refill-receiver member, the refill including an ink container-tube, a writing tip attached to a front end of the ink container-tube, and ink contained in the ink container-tube, a first cooperating mechanism provided in an interior of the rear end portion of the barrel for preventing the refill-receiver member from rotating relative to the barrel, a second cooperating mechanism provided in an interior of the rear end portion of the barrel for keeping the writing tip of the refill projected out of the barrel in use of the ball point pen, the refill-receiver member coupled to the second cooperating mechanism, and an actuator member provided at a portion of a peripheral wall of the barrel for causing the refill-receiver member to be advanced.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 This invention relates to a side knock-type ball point pen in which a
 writing tip is adapted to be projected out of a ball point pen barrel by
 operating actuator means which is received in an opening portion formed in
 a portion of a peripheral wall of the ball point pen barrel.
 2. Description of the Prior Art
 Hitherto, there have been proposed rear end knock-type ball point pens and
 side slide-type ball point pens. However, a side knock-type ball point pen
 is not proposed yet. An example of the side slide-type ball point pens is
 disclosed in Japanese Utility Model Application which was published under
 Publication No. 32394/1994 on Aug. 24, 1994.
 Referring now to FIG. 1, the conventional side slide-type ball point pen
 will be discussed in order to facilitate understanding of the present
 invention. The conventional side slide-type ball point pen includes a
 barrel 1, a head section 2 attached to a front end of the barrel 1, a
 refill 4 axially movably received in the barrel 1, a cam mechanism 5 for
 keeping a writing tip 4a of the refill 4 projected out of the head section
 2 in use of the ball point pen, the cam mechanism 5 provided in a portion
 of an interior of the barrel 1 which positionally corresponds to a portion
 of the barrel 1 which is to be gripped by a user in use, and a slide plate
 6 slidably received in an elongate hole 7 which is formed in a portion of
 a peripheral wall of the barrel 1, the slide plate 6 coupled to the cam
 mechanism 5. In the conventional ball point pen, the writing tip 4a of the
 refill 4 is projected out of the head section 2 by causing the slide plate
 6 to be slid along the elongate hole 7 and kept projected out of the head
 section 2 by the cam mechanism 5.
 In the conventional ball point pen, the cam mechanism which is complex in
 construction is disposed at the portion of the interior of the barrel 1
 which positionally corresponds to the portion of the barrel 1 which is to
 be gripped by the user, so that the portion of the barrel 1 which is to be
 gripped by the user is inevitably fat. This causes the user to be fatigued
 in use of the ball point pen and causes an appearance of the ball point
 pen to be unshapely. In addition, since the cam mechanism 5 is complex in
 construction, it takes a lot of labor to incorporate the cam mechanism 5
 into the barrel 1. Therefore, manufacturing cost of the ball point pen
 rises.
 SUMMARY OF THE INVENTION
 The present invention has been made with a view to overcoming the foregoing
 problems of the prior art ball point pen.
 It is therefore an object of this invention to provide a side knock-type
 ball point pen in which a portion of a barrel of the side knock-type ball
 point which is to be gripped by a user in use of the ball point pen is not
 fat.
 It is another object of this invention to provide a side knock-type ball
 point pen which can ensure a user's comfortable gripping of a barrel of
 the ball point pen so as not to cause a user to be fatigued in use of the
 ball point pen.
 It is still another object of this invention to provide a side knock-type
 ball point pen which can be easily manufactured.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
 A side knock-type ball point pen according to the present invention will be
 discussed hereinafter with reference to the accompanying drawings.
 Referring to FIGS. 2 and 3, there is illustrated a side knock-type ball
 point pen according to a first embodiment of the present invention. The
 ball point pen generally includes a barrel 10, a head section 20 attached
 to a front end portion of the barrel 10, refill-receiver means 30 axially
 movably incorporated within the barrel 10, a refill 40 removably received
 in the refill-receiver means 30, the refill 40 comprising an ink
 container-tube 400, a writing tip 402 attached to a front end of the ink
 container-tube 400, and ink contained in the container-tube 400, first
 cooperating means on the barrel 10 and the refill-receiver means 30 for
 preventing the refill-receiver means 30 from rotating relative to the
 barrel 10, second cooperating means 50 provided in an interior of the
 barrel 10 for keeping the writing tip 402 of the refill 40 projected out
 of the head section 20 in use of the ball point pen, the refill-receiver
 means 30 being coupled to the second cooperating means 50, and actuator
 means 60 for causing the refill-receiver means 30 to be moved forwardly.
 In the illustrated embodiment, the barrel 10 is produced by two-color
 molding or double shot molding. The barrel 10 comprises an elongated
 cylindrical body 100. The cylindrical body 100 has an opening portion 102
 formed in a region of a peripheral wall of the elongated cylindrical body
 100 and an inner circumferential step portion 104 provided around an inner
 peripheral portion of the cylindrical body 100 which is adjacent the front
 end of the cylindrical body 100.
 Referring to FIGS. 4 and 5, there is illustrated the refill-receiver means
 30. The refill-receiver means 30 comprises a cylindrical body 300 having
 an opened end and a closed end, an enlarged outer diameter portion 302
 provided around the opened end of the cylindrical body 300, a flange
 portion 304 provided around the closed end of the cylindrical body 300,
 and an engaging protrusion 306 provided at the closed end of the
 cylindrical body 300. The engaging protrusion 306 comprises a stem portion
 308 projecting rearwardly from the closed end of the cylindrical body 300,
 and a substantially cone-shaped portion 310 provided at a free end of the
 stem portion 308. The enlarged outer diameter portion 302 has a slant
 surface 312 which is inclined relative to a longitudinal axis of the
 cylindrical body 300 and slopes in a rearward direction, and projections
 314 provided on both sides of the enlarged outer diameter portion 302 and
 projecting laterally from the both sides of the enlarged outer diameter
 302.
 As shown in FIGS. 4 and 6A, the first cooperating means comprises a pair of
 axially extending guide grooves 316 formed in the both side of the
 enlarged outer diameter portion 302 of the refill-receiver means 30 (only
 one guide groove 316 is shown in FIG. 4), and a pair of axially extending
 ribs 106 provided on inner surface portions of the cylindrical body 100
 which are opposite to each other. The refill-receiver means 30 is
 incorporated within the barrel 10 with the guide grooves 316 of the
 enlarged outer diameter portion 302 being engaged with the axially
 extending ribs 106 of the barrel 10, so that the refill-receiver means 30
 can be axially moved along the axially extending ribs 106 of the barrel
 10, but the refill-receiver means 30 is prohibited to rotate relative to
 the barrel 10.
 Referring now to FIG. 6B, there is illustrated a modification of the first
 cooperating means. The modification is different from the first
 cooperating means of FIGS. 4 and 6A in that a pair of axially extending
 guide grooves 110 of the modification are formed in inner surface portions
 of the cylindrical body 100 which are opposite to each other, and a pair
 of axially extending ribs 350 of the modification are provided at the both
 sides of the enlarged outer diameter portion 302 of the refill-receiver
 means 30.
 As shown in FIG. 4, the enlarged outer diameter portion 302 of the
 refill-receiver means 30 further has a pair of introducing grooves 318
 which are formed in the both sides of the enlarged outer diameter portions
 302 and spread forwardly from ends of the guide grooves 316 as
 continuations of the guide grooves 316 (only one introducing groove 318 is
 shown in FIG. 4). The introducing grooves 318 of the enlarged outer
 diameter portion 302 serve as means to facilitate introducting of the ribs
 106 of the barrel 10 into the guide grooves 316 of the enlarged outer
 diameter portion 302 when the refill-receiver means 30 is incorporated
 into the barrel 10. The refill-receiver means 30 incorporated within the
 barrel 10 is in point-contact with an inner surface of the barrel 10 at
 the laterally protruding projection 314, so that friction force which may
 be produced during axial movement of the refill-receiver means 30 can be
 reduced. Therefore, the refill-receiver means 30 can be smoothly slid
 within the barrel 10. The cylindrical body 300 of the refill-receiver
 means 30 has a pair of elongated holes 320 formed in regions of a
 peripheral wall of the cylindrical body 300 which are adjacent the flange
 portion 304 and opposite to each other, and a pair of inwardly protruding
 portions 322 provided on inner surface regions of the peripheral wall of
 the cylindrical body 300 which are opposite to each other (see FIG. 5).
 The elongated holes 320 and the inwardly protruding portions 322 are
 alternately disposed around the peripheral wall of the cylindrical body
 300. The inwardly protruding portions 322 serve as means to tightly hold
 the ink container-tube 400 of the refill 40 when the refill 40 is inserted
 in the cylindrical body 300 of the refill-receiver mean 30. The peripheral
 wall portions of the cylindrical body 300 in which the elongated holes 320
 are formed can be deformed radially. Therefore, although the cylindrical
 body 300 has the inwardly protruding portions 322, the insertion of the
 refill 40 into the cylindrical body 300 of the refill-receiver means 30
 can be easily performed while causing the peripheral wall portion of the
 cylindrical body 300 to be deformed outwardly.
 Again referring to FIGS. 2 and 3, disposed between the inner
 circumferential step portion 104 of the barrel 10 and a circumferential
 step portion 324 of the refill-receiver means 30 (FIGS. 4 and 5) is a
 first spring 130 which always urges the refill-receiver means 30, having
 the refill 40 receiver therein, in the rearward direction.
 The second cooperating means 50 comprises a circumferential cam body 70
 formed around an inner peripheral portion of the barrel 10 which is
 adjacent a rear end of the barrel 10, a first cam element 80 incorporated
 within the barrel, and a second rotary cam element 90 incorporated within
 the barrel 10.
 Referring now to FIGS. 7 and 8, the cam body 70 comprises axially extending
 ridge portions 700 which are provided on and spaced apart from one another
 around the inner peripheral portion of the barrel 10, first axially
 extending recess portions 704 between corresponding adjacent axially
 extending ridge portions 700, and second axially extending recess portions
 706 between corresponding adjacent axially extending ridge portions 700.
 The first recess portions 704 and the second recess portions 706 are
 alternately disposed around the inner peripheral portion of the barrel 10.
 The second recess portions 706 are deeper than the first recess portions
 704. Each of the second recess portions 706 has a bottom surface lying on
 the same surface as the inner surface of the barrel 10 does, whereas each
 of the first recess portions 704 has a bottom surface higher than the
 inner surface of the barrel 10. An edge 710 of each of the axially
 extending ridge portions 700 which is adjacent the front end of the barrel
 10 is slanted and slopes in a rearward direction around the peripheral
 wall of the barrel 10. Similarly, an edge 704a of the bottom of each of
 the first recess portions 704 which is adjacent the front end of the
 barrel 10 is slanted at the same angle as the corresponding adjacent
 axially extending ridge portions 700 are done, and extends from the edge
 710 of one of the corresponding adjacent axially extending ridge portions
 700 to a side of the other of the corresponding adjacent axially extending
 ridge portions 700. As shown in FIG. 3, an inner circumferential step
 portion 160 is provided around the inner peripheral portion of the barrel
 10 and disposed in close proximity to a rear portion of the cam body 70.
 Referring to FIGS. 9 to 12, there is illustrated the first cam element 80.
 The first cam element 80 comprises a substantially tubular body 800 having
 first and second ends 802, 804, and an enlarged outer diameter portion 806
 provided around the first end 802 of the tubular body 800. The enlarged
 outer diameter portion 806 of the first cam element 80 has a saw-toothed
 edge 808 formed along an edge thereof, which is adjacent the first end 802
 of the tubular body 800, and facing the second end 804 of the tubular
 body, and axially extending ridge portions 810 provided around an outer
 periphery of the enlarged outer diameter portion 806 and spaced apart from
 one another around the outer periphery of the enlarged outer diameter
 portion 806. As shown in FIGS. 11 and 12, the tubular body 800 of the
 first cam element 80 has a pair of thick-walled sections 812 at portions
 thereof which are adjacent the second end 804 of the tubular body 800 and
 opposite to each other.
 Referring to FIGS. 13 to 15, there is shown the second rotary cam element
 90. The second rotary cam element 90 comprises a substantially tubular
 body 900 having first and second ends 902, 904, axially extending ridge
 portions 906 which are provided around an outer periphery of the tubular
 body 900, spaced apart from one another around the outer periphery of the
 tubular body 900, and extend along a total length of the tubular body 900,
 an outer circumferential rib 908 provided around the first end 902 of the
 tubular body 900, and a saw-toothed portion 910 formed along an edge of
 the second end 904 of the tubular body 900 which includes edges of the
 axially extending ridge portions 906.
 Again referring to FIGS. 2, 3 and 7 to 15, the first cam element 80 is
 incorporated in the barrel 10 with the tubular body 800 thereof being
 mounted on or connected to the engaging protrusion 306 of the
 refill-receiver means 30 and with the axially extending ridge portions 810
 thereof being engaged with the second recess portions 706 of the cam body
 70 which are deeper than the first recess portions 704 of the cam body 70.
 The tubular body 800 of the first cam element 80 has the opposite
 thick-walled sections 812 as discussed above, so that the tubular body 800
 is tightly mounted on the engaging protrusion 306 of the refill-receiver
 means 30. The axially extending ridge portions 810 of the first cam
 element 80 are engaged with the second recess portions 706 of the cam body
 70 as described above, so that rotational movement of the first cam
 element 80 relative to the barrel 10 is prevented. The first cam element
 80 is abutted against the circumferential step portion 160 of the barrel
 10 due to an action of the first spring 130, whereby the first cam element
 80 is prohibited to be separated from the cam body 70.
 The second rotary cam element 90 is rotatably mounted on the tubular body
 800 of the first cam element 80 with the saw-toothed portion 910 thereof
 facing the saw-toothed portion 808 of the first cam element 80 and with
 the axially extending ridge portions 906 thereof being engaged with the
 second recess portions 706 of the cam body 70. As shown in FIGS. 2 and 3,
 the second rotary cam element 90 has an inner circumferential step portion
 912 provided around an inner peripheral portion of the tubular body 900
 thereof. Disposed between the flange portion 304 of the refill-receiver
 means 30 and the inner circumferential step portion 912 of the second
 rotary cam element 90 is a second spring 170 which acts as means to
 facilitate rotational movement of the second rotary cam element 90 as will
 be described in greater detail hereinafter. Due to an action of the second
 spring 170, the saw-toothed portion 910 of the second rotary cam element
 90 is abutted against the saw-toothed portion 808 of the first cam element
 80. More particularly, vertices of the saw-toothed portion 808 of the
 first cam element 80 come into contact with areas between vertices and
 valley bottoms of the saw-toothed portion 910 of the second rotary cam
 element 90, and vertices of the saw-toothed portion 910 of the second
 rotary cam element 90 come into contact with areas between vertices and
 valley bottoms of the saw-toothed portion 808 of the first cam element 80.
 The second spring 170 is required to have force weaker than that of the
 first spring 130. If the force of the second spring 170 is stronger than
 that of the first spring 130, the second cooperating means 50 will be
 unable to perform a predetermined operation.
 As shown in FIGS. 2 and 3, the actuating means 60 for causing the axially
 movable refill-receiver means 30 to be moved forwardly is pivotally
 supported at the opening portion 102 of the barrel 10. More particularly,
 the actuator means 60 has a substantially inverted U-shaped body in
 cross-section. The inverted U-shaped body of the actuator means 60 has
 notches 600 (only one notch 600 is shown in FIGS. 2 and 3) formed in both
 sides of the inverted U-shaped body. The actuator means 80 is fitted in
 the opening portion 102 of the barrel 10 with the notches 600 receiving a
 supporting projection 180 of the opening portion 102 of the barrel 10 and
 with a part of the actuator means 60 being in contact with the slant
 surface 312 of the enlarged outer diameter portion 302 of the
 refill-receiver means 30, so that the actuator means 60 can be pivoted
 radially relative to the barrel 10 when the actuator means 60 is pushed
 inwardly of the barrel 10 by a user. When the actuator means 60 is pushed
 inwardly of the barrel 10 by the user, the refill-receiver means 30 having
 the refill 40 received therein is forwarded, whereby the writing tip 402
 is operatively projection out of the head section 20.
 As shown in FIGS. 2 and 3, a tail crown 190 is fitted in the rear end
 portion of the barrel 10. The tail crown 190 includes a tubular body 192
 having an opened end and a closed end, and a clip 194 for clipping the
 ball point pen to a shirt or jacket pocket or the like. The clip 194 is
 attached to and extends axially from a portion of an outer surface of the
 tubular body 192 which is adjacent the closed end of the tubular body 192.
 As best shown in FIG. 16, the tail crown 190 further has an engaging
 projection 196 of a substantially arrowhead-shape which is provided on a
 portion of the outer surface of the tubular body 192 which is opposite to
 the portion of the tubular body 192 to which the clip 194 is attached.
 Bearing on this, a notch 198 having a shape substantially identical to
 that of the engaging projection 196 is formed in the rear end of the
 barrel 10. The tail crown 190 is fitted in the rear end of the barrel 10
 with the engaging projection 196 thereof being engaged with the notch 198
 of the barrel 10, so that the tail crown 190 is prohibited to rotate
 relative to the barrel 10.
 Referring to FIGS. 17 to 19, the operation of the ball point pen will be
 discussed hereinafter. When the actuator means 60 is pushed inwardly of
 the barrel 10 in order to cause the writing tip 402 of the refill 40 to be
 projected out of the head section 20, the refill-receiver means 30 having
 the refill 40 inserted therein is advanced. At this time, the first cam
 element 80 and the second rotary cam element 90 which are in a state shown
 in FIG. 17 are also forwarded while being guided by the second recess
 portions 706 of the cam body 70 with which the axially extending ridge
 portions 810 of the first cam element 80 and the axially extending ridge
 portions 906 of the second rotary cam element 90 are engaged. During the
 forward movement of the refill-receiver means 30, the axially extending
 ridge portions 906 of the second rotary cam element 90 are disengaged from
 the second recess portions 706 of the cam body 70. At this time, the
 second rotary cam element 90 comes into a state in which the second rotary
 cam element 90 can be freely rotated, and the second rotary cam element 90
 is slightly rotated in such a manner that valley regions and crest regions
 of the saw-toothed portion 910 of the second rotary cam element 90 are
 allowed to be engaged with crest regions and valley regions of the
 saw-toothed portion 808 of the first cam element 80, respectively, as
 shown in FIG. 18, since the second rotary cam element 90 is abutted
 against the first cam element 80 by the action of the second spring 170 as
 described above. In this condition, the actuator means 60 is released from
 the pushing, the refill-receiver means 30 having the first and second cam
 elements 80, 90 coupled thereto is moved rearwardly due to the action of
 the first spring 130. As soon as the refill-receiver means 30 is moved
 rearwardly, slant edges of the axially extending ridge portions 906 of the
 second rotary cam element 90 are abutted against the slant edges 710 of
 the axially extending ridge portions 700 of the cam body 70 and guided by
 the slant edges 710 of the axially extending ridge portion 700 of the cam
 body 70 toward the slant edges 704a of the first recess portion 704 of the
 cam body 70, whereby the second rotary cam element 90 is rotated and the
 slant edges of the axially extending ridge portions 906 of the second cam
 rotary cam element 90 come into engagement with the slant edges 704a of
 the bottoms of the first recess portions 704 of the cam body 70 which are
 higher than the inner surface of the barrel 10, as shown in FIG. 19. As a
 result, the writing tip 402 of the refill 40 received in the
 refill-receiver means 30 is kept projected out of the head section 20 as
 shown in FIG. 3. In this condition, the user can use the ball point pen
 for writing. When the writing tip 402 is to be retracted in the barrel 10,
 the actuator means 60 is pushed inwardly of the barrel 10 to cause the
 refill-receiver means 30 to be advanced. During the forward movement of
 the refill-receiver means 30, the axially extending ridge portions 906 of
 the second rotary cam element 90 are disengaged from the edges 704a of the
 first recess portions 704 of the cam body 70. As soon as the axially
 extending ridge portions 906 of the second rotary cam element 90 are
 disengaged from the edges 704a of the first recess portions 704 of the cam
 body 70, the second rotary cam element 90 is slightly rotated in such a
 manner that the valley regions and crest regions of the saw-toothed
 portion 910 of the second rotary cam element 90 are allowed to be engaged
 with the crest regions and valley regions of the saw-toothed portion 808
 of the first cam element 80, respectively. In this condition, when the
 actuator means 60 is released from the pushing, the axially extending
 ridge portions 906 of the second rotary cam element 90 are abutted against
 the slant edges 710 of the axially extending ridge portions 700 of the cam
 body 70 and guided toward the second recess portions 706 of the cam body
 70 by the slant edges 710 of axially extending ridge portions 700 of the
 cam body 70, whereby the second rotary cam element 90 is rotated and the
 axially extending ridge portions 906 of the second rotary cam element 90
 slip into the second recess portions 706 of the cam body 60. As a result,
 the writing tip 402 is retracted in the barrel 10.
 Referring to FIGS. 20 and 21, there is illustrated a second embodiment of
 the present invention. This embodiment is substantially similar to the
 first embodiment of FIGS. 2-19 except that the cam body 70 of the second
 cooperating means 50 is provided in an interior of the tubular body 192 of
 the tail crown 190. In the second embodiment of FIGS. 20 and 21,
 components which are substantially similar to those shown in FIGS. 2-19
 are designated with like reference numerals and the description of them is
 not repeated. Similarly, the second embodiment is operated in the same
 manner as the first embodiment is done. Therefore, the description of the
 operation of the second embodiment is not repeated.
 The terms and expressions which have been employed are used as terms of
 description and not of limitation, and there is no intention in the use of
 such terms and expressions of excluding any equivalents of the features
 shown and described, or portions thereof, but it is recognized that
 various modifications are possible within the scope of the invention
 claimed.