JP3783513B2 - Feeding pencil - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a double-chuck type feeding pencil, and more particularly to a feeding pencil that can reduce the remaining length of a lead that cannot be consumed in terms of function, that is, the remaining lead can be reduced as much as possible.
[0002]
[Prior art]
In general, the feeding pencil is provided so that a predetermined amount of lead can be fed through an operation in which the chuck housed in the main body barrel is advanced and retracted once, and the lead covers the front area of the feeding pencil. It is configured to project a predetermined amount through a thin tube disposed at the tip of the tapered portion to be formed.
[0003]
However, the capillary at the tip of such a feeding pencil itself does not have a gripping force against the core. Therefore, when the consumption of the lead advances to a length that the gripping force by the chuck does not reach, the lead moves in the axial direction within the thin tube, which becomes a factor that hinders stable writing. And the inconvenience that the core in this case becomes a remaining core and is wasted.
[0004]
Therefore, recently, a double-chuck type payout pencil in which chucks for applying a gripping force to the core are respectively arranged in two front and rear regions in the main body barrel has come to appear. This type of feeding pencil is arranged in a main body shaft cylinder, a back chuck and a front position of the back chuck, is arranged on substantially the same axis as the back chuck, and the tip slightly protrudes from the tapered portion. The front chuck itself is configured to give a gripping force to the core itself. Therefore, even if the consumption of the lead progresses and the gripping force of the back chuck does not reach, the front chuck demonstrates its own gripping force, so it is possible to stably maintain the axis position of the lead, It is possible to reduce the remaining core amount as much as possible.
[0005]
[Problems to be solved by the invention]
However, in the known double chuck type feeding pencil, when the back chuck and the front chuck are arranged apart from each other in the axial direction, the lead has a length extending over the back chuck and the front chuck. The core is liable to be twisted, which causes breakage of the core.
[0006]
In addition, an intermediate member for maintaining the linearity of the back chuck and the front chuck along the same axis is required, which not only increases the number of parts, but also inconveniences that the assembly is complicated.
[0007]
OBJECT OF THE INVENTION
The present invention has been devised by paying attention to such inconveniences, the purpose of which is to prevent twisting of the length of the core straddling between the back chuck and the front chuck, and An object of the present invention is to provide a double chuck type feeding pencil that can avoid waste by reducing the amount of the remaining core as much as possible.
[0008]
Another object of the present invention is to provide a feeding pencil that can reduce the number of parts so that the linearity between the back chuck and the front chuck can be easily maintained.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a double chuck including a back chuck disposed inside a main body shaft cylinder so as to be movable in the axial direction, and a front chuck provided at a front position of the back chuck. In the chuck type feeding pencil,
The front chuck and the back chuck have a configuration in which they are arranged in the axial direction with their front part and rear part in contact with each other. With such a configuration, it becomes possible to ensure the continuity between the back chuck and the front chuck, and even if the chuck moves forward and backward with the core straddling between the two, the conventional twisting occurs. This makes it difficult to break the core. In addition, since the chucks are in contact with each other, an intermediate member for causing the front chuck to follow the operation of moving the back chuck forward can be eliminated, and the number of parts can be reduced.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The front chuck according to the present invention is supported by a tapered portion fixed to the front portion of the main body shaft cylinder, and a guide is provided on the inner peripheral surface of the tapered portion so that the axis of the front chuck coincides with the axis of the back chuck. It is preferable to adopt a configuration. With such a configuration, it is possible to arrange the above-mentioned chucks on the same axis line by simply fixing the tapered portion to the main body barrel, and consequently, the lead feeding operation can be performed smoothly. .
[0011]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0012]
FIG. 1 is an overall configuration diagram showing a cross section of a part of a double chuck type payout pencil according to the present embodiment. In this figure, a feeding pencil 10 is arranged in a main body shaft cylinder 12 provided with a clip 11 at a rear outer peripheral portion, a tapered portion 13 provided on the front end side of the main body shaft cylinder 12, and the main body shaft cylinder 12. The back chuck 15 and a front chuck 16 disposed in front of the back chuck 15 are provided. The core 20 is provided so as to be fed out by a predetermined amount through the back chuck 15 and the front chuck 16.
[0013]
The back chuck 15 has a rear end portion supported by the support cylinder 17 and is provided with a passage 15A that is connected to the central passage 17A of the support cylinder 17 on the same line. The back chuck 15 is provided so as to be able to move forward by a predetermined amount together with the holding cylinder 17 by pushing the knock 21 protruding from the rear end of the main body cylinder 12. A sleeve 25 is disposed on the outer peripheral side of the back chuck 15, and a chuck ring 23 is attached to the inner periphery of the front portion of the sleeve 25. The sleeve 25 is provided in a shape having a large diameter portion 25A that is in contact with the inner peripheral surface of the main body shaft cylinder 12 and a small diameter portion 25C that is continuous with the large diameter portion 25A via a step portion 25B. A coil spring 28 is disposed between the step portion 25B and the spacer 27 provided on the outer periphery of the support cylinder 17, whereby a force is applied to the back chuck 15 toward the rear of the main body shaft cylinder 12. Further, a screw groove 29 is formed on the outer peripheral side of the small diameter portion 25C, and the taper portion 13 can be screwed into the screw groove 29. The back chuck 15 is provided so that the center thereof coincides with the center of the front chuck 16 in a state where the back chuck 15 is assembled in the main body shaft cylinder 12.
[0014]
The front chuck 16 is provided with a shape having a passage 16A continuous on the same axis as the passages 15A and 17A at the center portion in the radial direction and a short cylindrical portion 30 on the base side. The short cylindrical portion 30 is supported in a state centered from the outer peripheral side by a rib-shaped guide 32 provided on the inner peripheral surface of the tapered portion 13, and is movable in the axial direction along the guide 32. Is provided. A spring receiving ring 34 is disposed on the inner peripheral surface of the front portion of the tapered portion 13, and a coil spring 36 is disposed between the spring receiving ring 34 and the front end surface of the short cylindrical portion 30, and the front chuck 16. A force is applied so that the rear end surface of the short cylindrical portion 30 contacts the tip of the back chuck 15. The front portion of the front chuck 16 is provided so that the maximum diameter portion 37 substantially coincides with the position of the front end surface 13A of the taper portion 13, thereby restricting the backward movement of the front chuck 16. .
[0015]
In the above configuration, each time the knock 21 is pushed once, the back chuck 15 and the front chuck 16 advance by a predetermined amount, and the lead 20 is guided and fed in the axial direction by the front chuck 16 in accordance with the advance amount. (See FIG. 4). At this time, since the back chuck 15 and the front chuck 16 are provided in a positional relationship in contact with each other, even if the core 20 has a length that straddles the chucks 15 and 16, the core 20 is twisted. It becomes difficult to generate , and the conventional breakage resulting from this can be solved reliably.
[0016]
Here, when the consumption of the lead 20 progresses and the lead 20 has a length that does not straddle between the chucks 15, 16, that is, when the lead 20 is supported only by the front chuck 16, The lead 20 is held by the unique gripping force of the front chuck 16. Accordingly, it is possible to restrict the axial movement of the core 20 while preventing the core 20 from being broken, and to consume the core 20 to the minimum length.
[0017]
Further, since the front chuck 16 supported in the taper portion 13 can be positioned on the same axis as the back chuck 15 while being held in a guide 32 formed on the inner peripheral surface of the taper portion 13, the taper portion 13 is tapered. By simply screwing and fixing the portion 13 to the body shaft cylinder 12 side, the chucks 15 and 16 can be positioned and assembled without using an intermediate member or the like, and disassembly can be easily performed.
[0018]
The feeding pencil 10 according to the present invention only needs to ensure continuity where the back chuck 15 and the front chuck 16 are in contact with each other, and the other components are not particularly limited and various design changes can be made. Is possible. For example, in the above-described embodiment, the lead 20 can be fed out by the pushing operation of the knock 21, but the present invention is also applied to a so-called side knock type feeding pencil in which a knock is provided on the outer peripheral surface portion of the main body barrel 12. can do.
[0019]
【The invention's effect】
As described above, according to the present invention, since the configuration in which the front portion of the front chuck and the rear portion of the back chuck are arranged in the axial direction is employed, the continuity between the back chuck and the front chuck is improved. Even if the chuck is advanced and retracted with the lead straddling between the two, it becomes difficult to cause twisting as in the conventional case, and breakage of the lead can be prevented. In addition, since the chucks are in contact with each other, an intermediate member for causing the front chuck to follow the operation of moving the back chuck forward can be eliminated, and the number of parts can be reduced.
[0020]
Further, according to the configuration in which the guide for aligning the axis of the front chuck with the axis of the back chuck is provided on the inner peripheral surface of the tapered portion fixed to the front portion of the main body shaft tube, the taper portion is fixed to the main body shaft tube. Thus, the chucks described above can be arranged on the same axis while being in contact with each other, and as a result, the lead feeding operation can be performed smoothly.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing a cross-section of a part of a feeding pencil according to an embodiment.
FIG. 2 is an enlarged cross-sectional view of a main part of FIG.
FIG. 3 is a schematic perspective view of a front chuck.
FIG. 4 is an enlarged cross-sectional view of a main part during a core feeding operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Leading pencil 12 Main body axial part 13 Tapered part 15 Back chuck 16 Front chuck 20 Core

Claims (2)

In a double chuck type payout pencil provided with a back chuck disposed inside the main body barrel and movable in the axial direction, and a front chuck provided at a front position of the back chuck,
The feeding pencil, wherein the front chuck and the back chuck are arranged in an axial direction in a state where their front and rear portions are in contact with each other. The front chuck is supported by a taper portion fixed to the front portion of the main body shaft cylinder, and a guide is provided on the inner peripheral surface of the taper portion so that the axis of the front chuck coincides with the axis of the back chuck. The feeding pencil according to claim 1, wherein the feeding pencil is characterized.

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