Lead Cartridge and Writing Tool into which Lead Cartridge is to be Incorporated

Abstract

A lead cartridge capable of holding a rod-shaped object of a sufficient length and allowing simultaneous replacement of the lead and the rod-shaped object is to be provided. A lead cartridge which includes a lead tank for containing leads and is detachably incorporated into a mechanical pencil to supply leads has a rod-shaped object feeding mechanism which propels the rod-shaped object by turning manipulation. This rod-shaped object feeding mechanism is configured of a spiral groove formed in the inner circumferential surface of a case comprising the lead tank, a guide sleeve which is arranged in the case to be unable to move in the axial direction and able to turn relative to the case and in which guide holes extending in the axial direction are formed, and a receptacle which is slidably fitted into the guide holes of the guide sleeve and has a male thread screwing into the spiral groove. A rod-shaped object is held by the receptacle. When the lead cartridge is incorporated into a mechanical pencil, the case becomes unable to turn relative to the outer sleeve of the mechanical pencil, and part of the guide sleeve protrudes out of the mechanical pencil.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an overall view of a lead cartridge, which is a preferred embodiment of the present invention;

FIG. 2 is a longitudinal sectional view of the lead cartridge shown in FIG. 1;

FIG. 3 is a longitudinal sectional view of a case;

FIG. 4A is a plan view, and FIG. 4B a sectional view, of a guide sleeve;

FIG. 5 is a plan view, FIG. 5B a front view and FIG. 5C a sectional view, of an eraser receptacle;

FIG. 6 is a sectional view showing a state in which the lead cartridge shown in FIG. 1 is incorporated into a mechanical pencil;

FIG. 7 is a longitudinal section of the body of an outer sleeve;

FIG. 8 is a longitudinal sectional view of a chuck joint;

FIG. 9 is a sectional view of a variation of the chuck joint;

FIGS. 10A and 10B are sectional views showing the procedure of linking the lead cartridge with the chuck joint;

FIG. 11 shows another side view of a mechanical pencil into which the lead cartridge is incorporated;

FIG. 12 is a longitudinal sectional view of a lead cartridge, according to another preferred embodiment of the invention;

FIG. 13 shows an exploded view of the lead cartridge shown in FIG. 12;

FIG. 14 is an exploded longitudinal sectional view of the lead cartridge shown in FIG. 12

FIG. 15 is a sectional view showing a state in which the lead cartridge shown in FIG. 12 is incorporated into a mechanical pencil; and

FIG. 16 is a longitudinal sectional view of a lead cartridge, according to still another preferred embodiment of the invention;

FIG. 17 shows an exploded view of the lead cartridge shown in FIG. 16; and

FIG. 18 is a sectional view showing a state in which the lead cartridge shown in FIG. 16 is incorporated into a mechanical pencil.

Claims

1. A lead cartridge including a tank for containing leads and adapted to be detachably incorporated into a writing tool to supply leads, comprising: a rod-shaped object feeding mechanism for propelling a rod-shaped object by a turning manipulation.

2. The lead cartridge according to claim 1, wherein said rod-shaped object feeding mechanism comprises a spiral groove formed in the inner circumferential surface of a case comprising said tank, a guide sleeve which is disposed within the case so as to be unmovable in the axial direction and rotatable relative to the case and is formed with a guide hole extending in the axial direction, and a receptacle for holding the rod-shaped object, said receptacle being slidably fitted into the guide hole of the guide sleeve and having a male thread screwing into said spiral groove, wherein when the lead cartridge is incorporated into the writing tool, the case becomes unable to turn relative to an outer sleeve of the writing tool, and part of the guide sleeve protrudes from the writing tool to be subjected to turning manipulation.

3. The lead cartridge according to claim 1, wherein said rod-shaped object feeding mechanism comprising a guide sleeve which is coupled to a case comprising said tank so as to be unmovable in the axial direction and unrotatable relative to the case and is formed with a guide hole extending in the axial direction, a spiral sleeve which is arranged on the outer circumferential side of the guide sleeve so as to be unmovable in the axial direction and rotatable relative to the guide sleeve and is formed in an inner circumferential surface with a spiral groove, and a receptacle for holding a rod-shaped object, said receptacle being slidably fitted into the guide hole of the guide sleeve and having a male thread screwing into said spiral groove, wherein when the lead cartridge is incorporated into the writing tool, the case becomes unable to turn relative to an outer sleeve of the writing tool and part of the spiral sleeve protrudes out of the writing tool to be subjected to turning manipulation.

4. The lead cartridge according to claim 1, wherein said rod-shaped object feeding mechanism comprising a spiral sleeve which is coupled to a case comprising said tank so as to be unmovable in the axial direction and unrotatable relative to the case and is formed in an inner circumferential surface with a spiral groove, a guide sleeve which is arranged on the inner circumferential side of the spiral sleeve so as to be unmovable in the axial direction and rotatable relative to the spiral sleeve and is formed with a guide hole extending in the axial direction, and a receptacle for holding a rod-shaped object, said receptacle being slidably fitted into the guide hole of the guide sleeve and having a male thread screwing into said spiral groove, wherein when the lead cartridge is incorporated into the writing tool, the case becomes unable to turn relative to an outer sleeve of the writing tool and part of the guide sleeve protrudes out of the writing tool to be subjected to turning manipulation.

5. The lead cartridge according to claim 2, wherein said guide sleeve engages with an engaging portion formed on the circumferential surface of the case comprising said tank to be held so as to be unmovable in the axial direction within the case.

6. The lead cartridge according to claim 3, wherein said guide sleeve engages with an engaging portion formed on the circumferential surface of the case comprising said tank to be held so as to be unmovable in the axial direction within the case.

7. The lead cartridge according to claim 4, wherein said spiral sleeve engages with an engaging portion formed on the circumferential surface of the case comprising said tank to be held so as to be unmovable in the axial direction within the case.

8. The lead cartridge according to claim 1, wherein a display part on which lead information regarding leads contained in said tank is displayed is provided on the outer circumferential part of the lead cartridge.

9. The lead cartridge according to claim 1, wherein at least part of the case comprising said tank is composed of a transparent material which makes visible the inside of the tank.

10. A writing tool into which the lead cartridge according to claim 8 is to be incorporated, comprising an outer sleeve and wherein the lead cartridge is made visible through at least part of the outer sleeve of the writing tool.

11. A writing tool into which the lead cartridge according to claim 9 is to be incorporated, comprising an outer sleeve and wherein the lead cartridge is made visible through at least part of the outer sleeve of the writing tool.

12. The writing tool according to claim 10, wherein said at least part of the outer sleeve of the writing tool is composed of a transparent material and the part composed of the transparent material comprising a lens.

13. The writing tool according to claim 11, wherein said at least part of the outer sleeve of the writing tool is composed of a transparent material and the part composed of the transparent material comprising a lens.