JPH0343034Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial field of application) This invention allows a lead protection tube to freely slide, which has a lead holding part and a feeding mechanism configured to feed out the lead by advancing and retracting the chuck inside the shaft cylinder. Regarding the attached sharpening pencil.

(Prior art) This kind of sharpening pencil was developed in the 1970s.
No. 10829, No. 56-15028, etc., but in both cases, since the core protection tube protrudes from the end tube, there is a risk that the core protection tube may be bent or damaged if dropped, and the end tube may be damaged when not in use. It needs to be stored inside. Conventional storage methods involve pushing the chuck protruding from the end of the barrel, expanding the chuck forward, pushing the core protection tube into the end barrel with your fingers, and then retracting the chuck to grasp the core. Let it store and hold. Alternatively, as disclosed in Japanese Utility Model Publication No. 55-37410, etc., there is a known structure in which the chuck is advanced longer than when the lead is fed out, and the chuck head is engaged with the lead protection tube and retracted and stored. ing.

(Problems to be Solved by the Invention) However, these sharp pencils have problems in that they are inconvenient to store, have a complicated structure, and as a result, their operation is uncertain. The purpose of this invention is to solve these problems and provide a sharpening pencil that is simple in structure and operation and provides reliable action.

(Means for solving the problem) This idea is to form a front sealing part by bringing the outer circumferential surface of the core protection tube and the inner circumferential surface of the end cylinder into close contact with each other in a slidable manner, and to A shaft that forms a sealed part after sealing the shaft cylinder and the feeding mechanism via a sealing member that can slide freely on the inner peripheral surface, and forms a space that can be sealed between the two sealed parts, and a shaft that forms the space. A through hole is formed in the cylinder or the feeding mechanism to communicate the space with outside air, and the space is configured to become a closed space when the through hole is closed.

That is, with the feeding mechanism advanced, the through hole is closed to create an airtight space, and then the feeding mechanism is retreated, and the core protection tube is sucked into the shaft cylinder using the vacuum pump action generated at that time. , which is intended to be stored and maintained.

(Example) FIGS. 1 to 3 show a first example showing different states.

Reference numeral 1 denotes a shaft cylinder, which consists of an end cylinder 3 and a main shaft 4 that are integrally connected via a relay cylinder 2. A core protection tube 5 is slidably mounted inside the end tube 3 and is composed of a core insertion tube 6 and a core holding member 7 made of an elastic material such as rubber and fixed to the rear part of the core insertion tube 6. The core holding member 7 has a flange 8 that is the same as or slightly larger than the inner diameter of the sliding hole 10 of the end tube 3, and is integrally formed with the flange 8 on the outer peripheral surface of the core protection tube 5, that is, in this embodiment, the outer periphery of the flange 8. The surface 9 is slidably brought into close contact with the inner circumferential surface of the end cylinder 3, that is, the inner circumferential surface 10' of the sliding hole 10, and the close contact portion is brought into close contact with the front sealing portion 1.
1. Reference numeral 12 denotes a known feeding mechanism that is slidably mounted inside the shaft cylinder 1 via the relay cylinder 2, and includes a clutch cylinder 13, a chuck 14 whose head is fitted into the clutch cylinder 13, and a chuck 14 and an end fitting 15. It consists of core storage tubes 16 that are connected through the core storage cylinders 16.
17 is a spring that springs the feeding mechanism 12 rearward, and 18 is a sealing member that also serves as a knob cylinder that is tightly fitted and fixed to the rear end of the shaft cylinder 1, and is formed into a bellows shape that can be expanded and contracted from an elastic material such as rubber. , inner peripheral surface 19 of shaft cylinder 1
A rear sealing part 21 seals between the outer peripheral surface 20 of the feeding mechanism 16, and a sealable space 22 is formed between the front sealing part 11 and the rear sealing part 21. Reference numeral 23 denotes a through hole that can be opened and closed and communicates with the outside air and the space 22, but when the through hole 23 is closed, the space 22 is configured to become a closed space. The through hole 23 is preferably provided at a position where it can be easily operated, such as at the rear end of the sealing member 18 or at a gripping portion of the shaft tube 1.

To use the sharpening pencil of the present invention, with the through hole 23 open, press and release the sealing member 18, which also serves as a knob cylinder, and then press the feeding mechanism 12.
is moved forward and backward to feed out the lead 24 by a distance a, and at the same time, the lead protection tube 5 is advanced to protrude from the end tube 3. At this time, since the through hole 23 is opened, the air in the space 22 is not compressed or depressurized, and functions similar to a conventional sharp pencil.

Then, when writing in this state (Figure 1),
As the core 24 wears out, the core protection tube 5 retracts and the core 24 can be used continuously without breaking while the core protection tube 5 is retracted to correspond to the protrusion length.

Next, when storing the core protection tube 5 after use, the sealing member 18 is pressed to protrude the core protection tube 5 from the end cylinder 3 as shown in FIG.
While moving forward, seal the through hole 23 with your fingertips,
Then, as shown in FIG. 3, if the pressure on the sealing member 18 is released, it can be stored instantly. In other words, in order to release the pressure on the sealing member 18 while the space 22 is a sealed space, a depressurizing pump action is generated in the space 22 when the feeding mechanism 12 retreats due to the spring 17, causing the inner circumferential surface of the end cylinder 3 to slide. The core protection tube 5, which is slidably in close contact with the inner circumferential surface 10' of the hole 10, is sucked and stored. FIG. 4 shows another embodiment of the rear sealing part 122.

In this embodiment, an annular stepped portion 1 is provided at the rear end of the shaft tube 101.
An annular sealing member 118 made of an elastic material is clamped and fixed with a stopper ring 126, and the outer circumferential surface of a bottomed knob cylinder 127, which is configured as a part of the feeding mechanism and is fitted into the core storage cylinder 116, is slid. They are movably brought into close contact to form a rear sealing part 121.

In addition, a through hole 128 communicating with the sealable space 122 and the outside air is formed at a rear position from the sealed portion 121 at least a distance a that is the sliding distance of the feeding mechanism necessary for feeding out the lead. Therefore, when feeding out the lead, it is not necessary to slide the feeding mechanism 112 by a distance a or more, so that the through hole 123 is not closed and can be used as before. In addition, when storing the core protection tube 105 (not shown),
27 to move the feeding mechanism 112 forward by a distance a or more and then release the pressure, it is instantly retracted by the decompression pump action as in the previous embodiment. That is, when the feeding mechanism 112 moves forward by a distance a or more, the through hole 123 is sealed by the sealing member 118, and the space 122 becomes a sealed space, and when the feeding mechanism 112 moves back, a vacuum pumping action occurs.

This embodiment is easier to operate than the first embodiment. In addition, in this invention, if dimensional accuracy can be achieved in the parts, the outer circumferential surface of the core protection tube and the inner circumferential surface of the end cylinder, as well as the outer circumferential surface of the feeding mechanism and the inner circumferential surface of the shaft cylinder, can be directly connected without using an elastic material or sealing member. They may be slidably brought into close contact with each other. In addition, in order to enhance the sealing effect, a packing material can be interposed at the joint part of the barrel and grease can be interposed at the close contact part, and it can also be applied to the structure of a known core protection tube or a so-called side-knock type sharp pencil. .

(Effects of the Invention) Since the present invention is constructed as described above, the structure and operation are simple, reliable operation is obtained, and the problems of the prior art are solved.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the first embodiment; FIGS. 2 and 3 are partially omitted cross-sectional views showing the operation of the first embodiment;
FIG. 4 is a sectional view of essential parts of the present invention and other embodiments. 1,101...Shaft cylinder, 5,105...Core protection tube, 7...Core holding member, 9...Outer circumferential surface (core protection tube outer circumference), 10'...Inner circumference (end cylinder inner circumference) surface), 1
1... Front sealing part, 12, 112... Feeding mechanism, 18,
118... Sealing member, 19... Shaft cylinder inner peripheral surface, 2
0,120...Outer peripheral surface of the feeding mechanism, 21,121...
...Rear sealed part, 22,122...Space, 23,12
3...Through hole.

Claims (1)

[Scope of utility model registration request] In a sharp pencil that has a feeding mechanism configured to feed out a lead by moving the chuck forward and backward, and a lead protection tube having a lead holding part slidably attached inside the barrel, the outer circumferential surface and end of the lead protection tube. The inner peripheral surface of the part cylinder is slidably brought into close contact with each other to form a front sealing part, and the outer peripheral surface of the feeding mechanism and the inner peripheral surface of the shaft cylinder are slidably brought into close contact with each other, or the shaft cylinder and the feeding mechanism are connected through a sealing member. After sealing, a sealed part is formed, and a sealable space is formed between both the sealed parts, and a through hole is formed in the shaft cylinder or the feeding mechanism that forms the space to communicate the space with outside air. A sharpening pencil characterized in that the space is configured to become a sealed space when the hole is closed.