JPS6094396A - Chuck body for propelling pencil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a yack body for a mechanical pencil that allows for good gripping and release of the lead.

This type of chuck body can be either an integrally molded product or an integrally assembled product of multiple components, and in either case, it receives a spring that urges backward and is applied by the knocking action of a mechanical pencil. It has a proximal end portion that receives the thrust, a core clamping portion that is tightened by a tightening force toward the center obtained by converting the axial force of the spring, and an intermediate arm portion that connects the two portions. In the case of an integrally molded chuck body, a jig is pressed against the front part of the chuck body, which is divided into several parts in the longitudinal direction, to deform it into an expanded shape. After the shapes of the chuck body are integrally connected, the front part of the chuck body is spread out in an expanded shape. The desired core clamping can be achieved by forcibly deforming the expanded core clamping part using the tightening force directed toward the center obtained by converting the axial force of the spring described above. Furthermore, the core was released by the restoring elastic force of the core holding portion that was generated naturally by eliminating the above-mentioned tightening force.

The conventional chuck structure that relies on the restoring elastic force and forced deformation of the chuck body has the following drawbacks. =I One reason is that it takes much longer to force the chuck body to close against the restoring elastic force, so even if sufficient expansion is performed at first, it gradually expands. This is a problem of stagnation, where the degree of gap decreases and eventually the supply of wick from the wick tank gets stuck, making it impossible to replenish the wick smoothly. The other is anticipating this decline,
If a strong restoring elastic force is provided, the strength of the spring that applies the core clamping force against it must also be made stronger, which makes the knocking operation more difficult. The lead gnawing phenomenon caused by this became stronger, and the space between the gripping teeth became completely filled with lead powder caused by the lead gnawing phenomenon, making it impossible to hold the lead while resisting writing pressure.

The object of the present invention is to forcibly deform the core clamping portion expanded outward to clamp the core, and to release the core depending on the restoring elastic force. L,
It is an object of the present invention to provide a chuck body for a mechanical pencil that can properly and reliably clamp and release the lead without relying on anything.

The configuration of the present invention to achieve this object is such that the chuck body has a mating structure in which a plurality of chuck component pieces can swing at a swing fulcrum formed on the facing surface of the proximal end of each chuck component, and the swing fulcrum is The base end portion located at the rear serves as a conversion portion that converts the thrust force into a tightening force directed toward the center.

The present invention will be described below with reference to embodiments shown in the accompanying drawings.

FIG. 1 shows an example in which the chuck body 1 of the present invention is applied to a pole chuck mechanism of a mechanical pencil with a retractable tip, and FIG. 2 is an exploded perspective view of the chuck body 1 shown in FIG. 1. This chuck body 1 also has a force in the center direction obtained by converting the force in the axial direction of the rod's foot 11ゝη8. The core clamping part 2a which is tightened by the core clamping part 2a and both parts 2a.

It is the same as the conventional one in that it is provided with an intermediate arm part 21) that connects 2C. However, in the illustrated examples, it is remarkable that the two chuck component pieces 2.2 have a combined structure in which the two chuck components 2.2 are pivotable by the pivot points 3 formed on the opposing surfaces 2C and 2G. There are differences.

Now, regarding the method of constructing the swinging fulcrum 3, when the chuck component piece 2.2 swings, as long as no deviation occurs between the two pieces 2.2, mere contact may be sufficient. As an example of this case, the swing fulcrum 3 is configured by line contact in Figures 5-Δ and 5-D, and by surface contact in Figures 5-8 and 5-0. It shows. However, it is preferable to adopt means that can reliably prevent this deviation.
As shown in FIG. 2, the concave grooves 4.8 for insertion are formed in the base ends 2c, 2c of each chuck component piece 2.2. /1 Either the protrusions 3a and the receivers 83b are formed on the flat surfaces of both sides, or one base end 2c has two protrusions 3a' and the other base end 2G has two receivers 3b (as shown in the figure). (omitted), the protrusion 3a is received by the receiving seat 3b of the other party, or the proximal ends 20, 20 of the two chuck component pieces 2, 2 are opposite to each other as shown in FIG. The highly flexible bottle-shaped members 3c, 3c planted on the surface are covered so as to be received by a receiver W=3d formed at the other base end 2c. The example shown in FIG. 4, in which both the protrusion 3a and the seat 3b are knife-shaped and long in the lateral direction, can more reliably prevent wobbling than the example shown in FIG. 2.

In the present invention, the chuck component 2 centered on the swing fulcrum 3,
2 creates two states of clamping and releasing the core, so even though the chuck component pieces 2 and 2 are combined, the proximal ends 2, c, and 2c collide with each other and C core is clamped. Part 2a.

2a, an appropriate gap is provided between the chuck component pieces 2.2, or the base end portions 2c, 2c are connected to the base end portion 2c.

Appropriate warpage (=I is given to the part except 2C.

In order to tighten the ball-dock mechanism using such a chuck body 1, a ball seat 5 is formed on the outer surface of the core holding parts 2a, 2a, and a spring 8 installed inside an outer cylinder 7 with an inclined guide surface 6 is used to tighten the chuck. By pushing the body 1 backward, the ball 9 housed in the ball receiving seat 5 is pushed against the diagonal inner surface 6 of the outer cylinder 7 (σ!) and is suspended by the spring 8. The force in the axial direction of Instead of clamping the core, by applying a clamping force to the core clamping parts 2a, 2a located away from the swinging fulcrum 3, the core clamping parts 2a, 2a are joined around the swinging fulcrum 3. The core is clamped by rotating the Jitoku Suisei J'1'2.2.If the swing fulcrum 3 is a combination of the protrusion 3a and the seat 3b, the swing caused by the repeated swing motion is The wear and tear at the swing fulcrum 3 is almost negligible, and there is no problem of settling. By setting g1 so that the bottle-shaped member 3G stands up almost straight in the pinched state, the bending stress of the bottle-shaped member 3c is reduced even if the core clamped state is longer. can be made extremely small, so that the sagging of the bottle-shaped member 3C is not a problem.Furthermore, since the core holding parts 2a, 2a are not forcibly deformed as in the conventional case, the force of the spring 8 can also be weak. The knock operation is also light and easy to use.

Next, by the knocking operation operated by the user to feed out the lead, a thrust force resisting the force of the spring 8 is applied to the pusher 10, for example.
As a result, the point that the chuck body 1 is pushed forward is also the same as before. However, when the chuck body 1 moves forward due to the thrust force of the pusher 10, the clamping force at the lead clamping part decreases, and the lead clamping part automatically expands with the restoring elastic force developed in response to this. Unlike the conventional structure in which there was no need to provide the proximal end of the chuck body with a function for expanding the core holding part, in the present invention,
The base end portions 2C and 2C that correspond to the rear of the swing fulcrum 3 are the pusher 10.
Change the Jlf force given by to the clamping force directed toward the center Jf
The core clamping parts 2a, 2a, which are far away from the swing fulcrum 3, are actively expanded.

The other party whose base end portions 2C, 2C that correspond to the rear of the swing fulcrum 3 cooperate to convert the above-mentioned thrust into a tightening force directed toward the center may be each of the pushers 10 itself, or in the case of a ball-to-tsuta pusher. In that case, outer cylinder 7 may be used.

Furthermore, the spring 8 may be used. Base end 2C, 2C
The shape of the part can be easily designed to decompose the thrust force and obtain a component force directed toward the center, depending on the type and shape of the cooperating pusher 10, outer cylinder 7, or spring 8. . In the illustrated example, the base end 2 is located behind the swing fulcrum 3.
In the example shown in FIG. 1, the proximal end portions 2c, 2C1!
The two ends can be pressed by an inwardly tapered surface 12 formed on the distal annular portion 11 of the push tool 10, and in the example shown in FIG. A tapered surface 13 is formed which is pressed by one end edge.

Furthermore, when the chuck body 1 is pushed forward by the pusher 10, it cooperates with the outer cylinder 7 and the tail end of the spring 8 to obtain a tightening force directed toward the center. Tapered bulges 14.14 are formed at the rear ends of M ends 2C and 2C, which are pressed by the inner edge of the outer cylinder 7, and in the example shown in FIG. Inwardly tapered surface 1 of cylinder 7
A flange-like protrusion 16 is formed which is pressed by the flange 5. Furthermore, the fifth
In the example shown in FIGS. - and D, an overhang 18 having an inclined surface 17 pushed by the tail end of the spring 8 is formed at the rear end of the base end 20° 29. In either case, the thrust when a knocking action is applied against the force of the spring 8 will obtain a clamping force, which is a component force directed toward the center, and the proximal end that is behind the swing fulcrum 3 will be 20 and 20 are mutually displaced toward the center, the core clamping parts 2a' and 2a, which are far away from the swing fulcrum 3, are sufficiently faced.

The lead clamping parts 2a, 2a in the expanded state return to the closed state by the force of the spring 8 by stopping the knocking operation and releasing the finger. At that time, make sure that the concave grooves 4゜4 for the tailstock fit correctly.
If necessary, means for preventing displacement of the chuck component pieces 2.2 may be formed. In FIG. 5-A, the bar-shaped protrusion 19 protruding from one chuck component 2 and the guide hole 20 of the other chuck component 2 into which the bar-shaped protrusion 19 is inserted are shown.
2 shows an example of a means for preventing writing deviation. Further, when the swing fulcrum 3 is composed of a combination of a protrusion 3a and a catch 31),
If it is inconvenient to handle because the chuck component pieces 2 and 2 are not tied together and simply fit together, then attach the ceramic 21 to the proximal end as shown in Figure 5-A. 20, 20 and tied with an O-ring 22, the ring part at the rear end of the spring 8 can fit into the hard part 23.23 at the base end part 2C, 2C. It may be formed into

The explanation up to this point has been given as being applied to a ball chuck, but it is also applicable to a normal chuck mechanism.
Needless to say, it can be applied to more than one person.

As is clear from the above description, the chuck body according to the present invention departs from the method of chucking by the restoring elastic force and forced deformation of the chuck body, and instead includes the core clamping portion 2a in front of the swing fulcrum 3; By tightening 2a, the core is clamped, and by tightening the proximal end portions 2C and 20 behind the swing fulcrum 3, the core clamping parts 2a and 2a are opened, that is, the core is released. Since it is made of aluminum, there is no problem of so-called fatigue, and since the force of the spring 8 is sufficient, the knocking operation is light and the phenomenon of lead galling can be alleviated.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a knock-tip mechanical pencil using the chuck body of the present invention, Fig. 2 is an exploded perspective view of the chuck body shown in Fig. 1, and Figs. 3 and 4 are views of the chuck body. Exploded perspective views showing other embodiments, Figures 5-A to 5-
FIG. D is a cross-sectional view of essential parts showing different embodiments adopted to apply a clamping force toward the center of the proximal end of the chuck component. 1... Chuck body, 2... Chuck component piece, 2a.
... Core holding part, 2b... Intermediate arm part, 2c... Base end part, 3... Swinging fulcrum, 5... Ball receiver, 8... Spring, 9... Ball. Patent Applicant Pentel Co., Ltd. Agent Yukihito Omata Yudo Yunosuke Araki

Claims (1)

[Claims] 1. A proximal end portion that receives a spring that is biased backward and receives the thrust force given by the knocking action of the mechanical pencil, and a base end portion that converts the force in the axial direction of the spring. a core holding part that is tightened by the obtained center-directed force and has a ball seat on the outer surface so that the ball can be disposed;
In a mechanical pencil grip body consisting of an intermediate arm portion connecting both parts, the grip body is capable of swinging at a rocking fulcrum formed on a 14-part facing surface of each chuck component piece. A chuck body for a mechanical pencil, characterized in that it has a mating structure, and the base end portion behind the swinging fulcrum is a conversion portion that converts the thrust force into a tightening force directed toward the center. 2. The seat pencil according to claim 1, wherein the swinging fulcrum is constituted by a protrusion formed at the proximal end of one chuck component and a seat formed at the proximal end of the other chuck component. Chuck body. 3. The swing fulcrum is a highly flexible pin-shaped member implanted on the facing surface of the proximal end of each chuck component, claim 1.
Chuck body for mechanical pencil described in section. 4. The chuck body for a mechanical pencil according to claim 1, wherein the converting portion at the base end portion cooperates with a pusher pushed forward by a knocking action. 5. Is the conversion part of the proximal end part Balluna 1? A chuck body for a mechanical pencil according to claim 1, which cooperates with the outer cylinder of the chuck. A chuck body for a mechanical pencil according to claim 1. 7. A chuck body for a mechanical pencil according to claims 11n to 6, wherein an O-ring is arranged on the outer periphery of the proximal end of the chuck body.