Multiplex writing implement

• US 6,217,241 B1
• Filed: 04/30/1999
• Issued: 04/17/2001
• Est. Priority Date: 04/30/1999
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Pencil Kabushiki Kaisha
• Original Assignee: Mitsubishi Pencil Kabushiki Kaisha
• Inventors: Kobayashi, Seiichi
• Primary Examiner(s): Eloshway, Charles R.
• Application Number:
  US09/302,722
• Time in Patent Office: 718 Days
• Field of Search: 401/29, 401/31, 401/32, 401/33, 401/192, 401/209, 401/219
• US Class Current: 401/32
• CPC Class Codes: B43K 24/14 operated by turning means
• CPC Class Codes: B43K 25/028 combined with means for propelling, projecting or retracting the writing unit

Abstract

A multiplex writing implement has a multiple number of ball-point pen elements in the barrel cylinder thereof, in which an ink reservoir thereof is filled with a water based ink having so-called thixotropy, which is a characteristic which lowers the viscosity of ink as the tip ball rolls, allowing outflow of ink, or a low-viscosity oil based ink and which are configured so that their writing tips can selectively move in and out through the front end opening of a mouthpiece of the barrel cylinder, and is constructed such that at least the front part of the barrel cylinder is formed of a transparent resin molding and the mouthpiece which is opaque and tapered toward the front end is attached to the front of the barrel cylinder.

Claims

1. A multiplex writing implement comprising:

a barrel cylinder;

a mouthpiece extending from a front of the barrel cylinder, the mouthpiece being tapered toward a front end opening thereof;

a plurality of ball-point pen elements disposed within the barrel cylinder, each ball-point pen element having an ink reservoir which is filled with one of a water based ink having thixotropy or a low-viscosity oil based ink, each ball-point pen element being configured so that a writing tip thereof can selectively move in and out through the front end opening of the mouthpiece, each ball-point pen element having a point assembly at one end thereof,

at least a front part of the barrel cylinder being formed of a transparent resin molding and the mouthpiece being formed of an opaque material, wherein longitudinal grooves are formed at predetermined positions on the tapering inner surface of the mouthpiece and a ball holder of the point assembly is loosely inserted in the longitudinal groove when the writing tip moves in and out through the front end opening so that at least the ball holder is kept out of contact with the tapering inner surface of the mouthpiece.

2. The multiplex writing implement according to claim 1, wherein each ball-point pen element is configured so that the tip ball is continuously pressed into sealing contact with an inner brim of the ball holder at a top of the point assembly and a follower which is made of a nondrying greasy material is disposed within the ink reservoir at one end of the ink opposite the point assembly, the follower moving following consumption of the ink as writing proceeds.

3. The multiplex writing implement according to claim 1, wherein at least one of the ball-point pen elements is a ball-point pen for mistake correction and the ink is a white pigment ink which includes a white pigment and is formed so that the pigment is prevented from settling.

4. The multiplex writing implement according to claim 3, wherein the white pigment comprises a material selected from the group consisting of titanium oxide and hollow high polymer micro-particles.

5. The multiplex writing implement according to claim 1, wherein each ball-point pen element has a valve chamber in which a ball valve is loosely held therein facing a rear end of the point assembly and a rear part of the valve chamber comprises a ball seat with which the ball valve comes into sealing contact to prevent ink from flowing backward and a conduit communicating between the ball seat and the ink reservoir.

6. The multiplex writing implement according to claim 1, wherein each of the ball-point pen elements is disposed axially movable with respect to the barrel cylinder and a mechanism for moving back and forth the ball-pen elements in an alternating manner is provided, and the ink reservoir of the ball-point pen element is substantially non-deformable and is fitted so as not to sway within the barrel cylinder, and a joint connecting between the ink reservoir and the point assembly is formed with a deformable, flexible part.

7. A multiplex writing implement comprising:

a barrel cylinder;

a mouthpiece extending from a front of the barrel cylinder, the mouthpiece being tapered toward a front end opening thereof;

a plurality of ball-point pen elements disposed within the barrel cylinder, each ball-point pen element having an ink reservoir which is filled with one of a water based ink having thixotropy or a low-viscosity oil based ink, each ball-point pen element being configured so that a writing tip thereof can selectively move in and out through the front end opening of the mouthpiece, each ball-point pen element having a point assembly at one end thereof,

at least a front part of the barrel cylinder being formed of a transparent resin molding and the mouthpiece being formed of an opaque material, wherein a joint for joining the ink reservoir and the point assembly has a projection on a peripheral surface thereof which comes in contact with the tapering inner surface of the mouthpiece in such a manner that a ball holder of the point assembly is kept out of contact with the tapering inner surface of the mouthpiece when the writing tip moves in and out through the front end opening of the mouthpiece.

8. The multiplex writing implement according to claim 7, wherein each ball-point pen element is configured so that the tip ball is continuously pressed into sealing contact with an inner brim of the ball holder at a top of the point assembly and a follower which is made of a nondrying greasy material is disposed within the ink reservoir at one end of the ink opposite the point assembly, the follower moving following consumption of the ink as writing proceeds.

9. The multiplex writing implement according to claim 7, wherein at least one of the ball-point pen elements is a ball-point pen for mistake correction and the ink is a white pigment ink which includes a white pigment and is formed so that the pigment is prevented from settling.

10. The multiplex writing implement according to claim 9, wherein the white pigment comprises a material selected from the group consisting of titanium oxide and hollow high polymer micro-particles.

11. The multiplex writing implement according to claim 7, wherein each ball-point pen element has a valve chamber in which a ball valve is loosely held therein facing a rear end of the point assembly and a rear part of the valve chamber comprises a ball seat with which the ball valve comes into sealing contact to prevent ink from flowing backward and a conduit communicating between the ball seat and the ink reservoir.

12. The multiplex writing implement according to claim 7, wherein each of the ball-point pen elements is disposed axially movable with respect to the barrel cylinder and a mechanism for moving back and forth the ball-pen elements in an alternating manner is provided, and the ink reservoir of the ball-point pen element is substantially non-deformable and is fitted so as not to sway within the barrel cylinder, and a joint connecting between the ink reservoir and a point assembly is formed with a deformable, flexible part.

13. The multiplex writing implement according to claimed 7, wherein the joint has a flexible portion, and the projection is provided to the point assembly side with respect to the flexible portion.