JPS6129382A - Manually operable cutter - 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 manual cutter for cutting, for example, a linear or rod-shaped member to be cut by bringing two blades close to each other by manual operation, and in particular, by the action of a double lever. This invention relates to a type of manual cutter in which the manual operating force is increased and applied to the blade.

Traditionally, in general, manual cutters for cutting wire materials such as relatively thick wires, or bar materials such as bolts and reinforcing bars require a considerable amount of cutting force. ratio) needs to be increased. Therefore, in the past, a first lever means for boosting the manual operation force and a second lever means for further boosting the force boosted by the first lever means are provided to increase the manual operation force. A dual-lever type manual cutter is known that is enlarged in two stages so that it can be applied to the blade portion that participates in cutting.

E + <I'm going to do it. However, in such a conventional double-lever type cutter, the first lever means and the second lever means (IJ: /, etc. 0. More connected Awa7, -yu
I Because the structure was such that the set lever ratio could not be changed, if a large lever ratio was set to correspond to the area where the cutting load is large, the amount of operation would become large in the area where the load at the end of cutting is small. If the lever ratio is set small so as to suppress the amount of operation in a region where the load is small, there is a problem in that the amount of reduction in the operating force becomes small in a region where the cutting load is large.

In order to solve the above-mentioned problem, the present invention has a high lever ratio in areas where a large force is required when cutting, and a method in which a small force is sufficient for cutting. By automatically reducing the lever ratio, the operating force during cutting is reduced and the overall operating amount is shortened.

That is, the manual cutter according to the present invention includes (a) a main body having a blade portion at one end; (b) an intermediate portion attached to the main body so as to be relatively rotatable around a first axis; (C) a first lever having one end shorter than the other end across one axis, and having a blade at the one end that cooperates with the blade of the main body to perform a cutting action; An intermediate portion is attached to the main body so as to be relatively rotatable around a second axis parallel to the first axis, and one end is formed shorter than the other end across the second axis, and the one end a second lever that is brought into contact with the other end of the first lever and rotated relative to the main body, thereby rotating the first lever and bringing the two blade parts closer together; (d) is provided between the other end of the first lever and one end of the second lever, and in the process of bringing the two blades closer together, the first lever and the second lever The cam mechanism includes a cam mechanism that reduces the lever ratio by shifting the contact position with the second lever to the first axis side.

Operation - Tomo In such a manual cutter, in areas where the cutting load is large, the cam mechanism brings the first lever and the second lever into contact with each other at a contact position that provides a large leverage ratio, but near the end of cutting In a region where the load is small, the cam mechanism moves the contact position between the first lever and the second lever to the first axis side. As a result, both the lever ratio of the first lever and the lever ratio of the second lever become smaller at the same time.
The operating stroke during cutting is shortened without substantially increasing the manual operating force.

EMBODIMENT OF THE INVENTION Hereinafter, in order to clarify the present invention more specifically, one embodiment thereof will be described in detail based on the drawings.

FIG. 1 shows a front view of essential parts of a manual cutter that is an embodiment of the present invention, FIG. 2 shows a plan view thereof, and FIG. 3 shows a left side view thereof. ing. As is clear from FIGS. 1 and 2, this cutter includes a main body lever 10 having a longitudinal shape as a main body, and a first lever 12 and a second lever are connected in the longitudinal direction of the main body lever 10. 14 are provided. The first lever 12 is a relatively short lever compared to the second lever 14, and the middle part is attached to one end of the main lever 10 by a second shaft 16 around its axis ○, (first axis). It is attached so as to be relatively rotatable, and with this second shaft 16 in between,
A predetermined leverage ratio is provided by forming one end portion shorter than the other end portion.

One end of the first lever 12 and one end of the main lever 10 constitute the tips of the forceps, and these tips have blades 18 that cooperate with each other to perform a cutting action. each formed. Each of these blade parts 18 is formed at one end of a thick plate-shaped cutter blade 20 as shown in FIGS. The second shaft 1G passes through the center hole 22 of the first lever 12, and the second shaft 1G passes through the center hole 22 of the nut 24, as shown in FIG. are removably fixed to the main lever 10 and the first lever 12 by being tightened, and a force of 7 is applied.
are adapted to be brought into sliding contact with each other with virtually no gap occurring on their mating surfaces. Further, as is clear from FIG. 6, the cutting edge of each blade portion 18 is formed to be inclined with respect to the straight line A perpendicular to the center line (first axis OX) of the center hole 22, and the two blades When the portion 18 is approached, it closes from the distal end side.

In addition, each cutter blade 20 has a similar blade part 26 formed in line symmetry at the end opposite to the blade part 18 with respect to the center hole 22, so that the blade part 18 is worn out and becomes dull. If so, the cutter blade 20 can be turned over and the blade portion 26 can be used for cutting.

On the other hand, the second lever 14 is attached to the main body lever 10 through a second shaft 28 so as to be relatively rotatable around its axis 02 (second axis). This second shaft 28
is located at a predetermined distance from the second shaft 16 on the side opposite to the blade portion 18, and the second lever 14 is located at a predetermined distance from the second shaft 16.
8 on one end side, that is, the first lever 1 in FIG.
By forming the second end shorter than the other end, a predetermined leverage ratio is provided. The longer part of the second lever 1-2 is constructed by connecting a square pipe member 30 to a solid member constituting the vicinity of the second shaft 28, and the main body lever 10 is also constructed in a similar manner. The square pipe member 32 extends an equal distance from the second shaft 28 on the side opposite to the blade part 18, and a grip (not shown) is attached to the other end of the pipe member 32, so that the operator can grasp it with both hands. It consists of a pair of handles for operation. Further, the main body lever IO has an integral mounting bracket 34 that protrudes in a direction parallel to the rotational plane of the first lever 12 and the second lever 14, as shown in FIG. , through this one-piece bracket 34, the main body lever l
O can also be used in a state fixed to a predetermined fixing member.

FIG. 1 shows a state in which the two blade parts 18 cross each other after cutting is completed, but in the process of reaching this state, the second lever 14 rotates clockwise relative to the main lever 10. By being moved, one end of the second lever 14 pushes up the other end of the first lever l2 and rotates it counterclockwise, bringing the two blade parts 18 closer together, and then as shown in the figure. Set to cross state. As a result, the operating force for cutting is multiplied in two stages by the second lever 14 and the first lever 12, and is transmitted to the cutting section between the two blade sections 18.

One end of the second lever 14 and the other end of the first lever 12 are brought into contact via a cam mechanism. Next, this cam mechanism will be explained.

A first cam surface 36 and a second cam surface 38 are formed at the other end of the first lever 12 . The first cam surface 36 has a wear-resistant cam forming member 40 as shown in FIG. formed by being stopped,
If this first cam surface 36 is traced from the other end of the first lever 12, it first extends in a direction oblique to the longitudinal direction of the first lever 12 and extends along the first axis 0. The first lever 12 gradually approaches the 0° side of the first axis along the longitudinal direction of the first lever 12. Further, the second cam surface 38 is formed along one side edge of the first lever 12 in the longitudinal direction, and occupies a position closer to the first axis 01 than the first cam surface 36 .

On the other hand, a first cam roller 4 is attached to one end of the second lever 14.
2 and a second cam roller 44 are respectively rotatably attached around respective axes parallel to the first axis O8 and the second axis 02. The first cam roller 42 is located closer to the second axis 02 than the second cam roller 44, and is brought into contact with the first cam surface 36 from the beginning to near the end of cutting, as shown in FIG. , serves to rotate the first lever 12 in a direction in which the two blade parts 18 approach each other while rolling on the first cam surface 36 as the second lever 14 rotates relative to each other.

Further, the second cam roller 44 is brought into contact with the second cam surface 38 in place of the first cam roller 42 separating from the first cam surface 36 at the end of cutting, and is brought into contact with the second cam surface 38 . 38 serves to rotate the first lever 12 so that the two blade parts 18 cross each other.

The second cam roller 44 is connected to the first cam roller 4.
2 and the first cam surface 36 from the contact position of the first axis 0. The second cam surface 38 is brought into contact with the second cam surface 38 at a position closer to .

As a result, if the state changes from the state in which the first cam roller 42 is in contact with the first cam surface 36 to the state in which the second cam roller 44 is in contact with the second cam surface 38, the relationship between the second lever 14 and the first lever 12 is changed. While the contact position moves away from the second axis 02,
First axis 0! , the lever ratio of the second lever 14 and the lever ratio of the first lever 12 become smaller at the same time, so that as the second lever 14 rotates, the gap between the two blade parts 18 decreases. Because it gives a bigger movement.

Note that since the first cam surface 36 has a portion that is inclined with respect to the longitudinal direction of the first lever 12 and a portion that is parallel to the longitudinal direction of the first lever 12,
When the first cam roller 42 moves along the inclined part, the contact position (contact position) between the two gradually approaches the first axis O4, and when the first cam roller 42 moves along the parallel part, it approaches the first axis 01 even more. , even in the process of the first cam roller 42 transferring the first cam surface 36, the second cam roller 4
Although it is not as bad as 4, the leverage ratio will be reduced to some extent.

The other end of the first lever 12 is further provided with return cam surfaces 46 and 48. The return cam surface 46 is formed on one wall surface of the U-shaped cutout, facing a part of the first cam surface 36 and spaced therefrom by a distance greater than the diameter of the first cam roller 42. After completion of this, the first cam roller 42 is brought into contact with this return cam surface 46, and the first lever 12 is rotated in the direction to open the two blade parts 18.

Further, the return cam surface 48 is formed on the side edge of the first lever 12 opposite to the second cam surface 38, and the second lever 14 has a return cam roller 50 that is aligned with the second axis 02. The return roller 50 is rotatably mounted around a parallel axis, and near the end of the return process, the return roller 50 is returned as shown in FIG.

The second lever 1 contacts the cam surface 48, replaces the first cam roller 42, and moves the second lever 1 in the direction of further opening the two blade portions 18.
It is designed to rotate 2.

This return cam roller 50 is dedicated to opening the two blade parts 18, but the first cam roller 42 is used for both cutting and returning, and the second cam roller 44
is dedicated to cutting.

In the return process, the contact position between the return cam roller 50 and the return cam surface 48 is closer to the first axis 0□ side than the contact position between the first cam roller 42 and the return cam surface 46, so that the lever is increased accordingly. The ratio becomes smaller, and a larger movement is applied to the first lever 12. Also,
At the end of the return, the return cam roller 50 is brought into contact with the return cam surface 48, and the first cam roller 42 is brought into contact with the inclined portion of the first cam surface 36. As a result, the first cam roller 42 and the return cam roller 50 also serve as a stopper that defines the return limit of the first lever 12 and the second lever 14.

The cutter configured as described above can be suitably used to cut wire rods such as wires and wires, or bar materials such as reinforcing bars and bolts. When cutting, as shown in FIG. 9 ia
By rotating the blade relative to the main salary lever 10 clockwise in the figure, both blade parts 18 are brought closer together as shown in (b). Although the cutting load is large in the cutting process from (al to (bl), the first cam roller 42
contacts the first cam surface 36 and relatively rotates the second lever 12 counterclockwise, providing a large lever ratio commensurate with the cutting load. To give one specific example,
In the stage [a), the lever ratio is 108, and in the stage (b), the lever ratio is 76, and the operating force applied between the second lever 14 and the main body lever 10 is 108 in this case.
The force is increased by ~76 times and applied between the two blade portions 18, so that even if the cutting load is large, it does not cut, and cutting can be performed with a small operating force.

Also, in the process of bringing both blade parts 18 closer together,
, [(As is clear from bl, each blade part 18
Since the cutting blades are closed from the tip side, the member to be cut is prevented from slipping and detaching from between these blade parts 18.

Then, by further relatively rotating the second lever 14 from the stage (bl), the double-edged portion 1
8 disappears, and further, as shown in +d), both blade parts 18 are crossed so as to cross each other, and the blade parts 18 are fed. In this way, in the feeding process after the final stage of cutting, the load between both blade parts 18 becomes extremely small, and in the stage (C) of the final stage of cutting, the first cam roller 42 comes into contact with the first cam surface 36. Instead, the second roller 44 comes into contact with the second cam surface 38 and rotates the first lever 12, so that the second lever 1
4 and the first lever 12 shifts from the second axis 02 side to the first axis 0□ side, and as a result, the second lever 14
And the overall leverage ratio of the first lever 12 becomes smaller. For example, the lever ratio, which was 76 at the stage (bl), becomes 37 at the stage (C1), and as the second lever 14 is rotated, the second cam roller 44 moves the second cam surface 38 along the first axis Ol. By transferring to the side of , the lever ratio at the end of the feed stage in (d) becomes, for example, 35.

Thus, a large cutting force is required (al, (b
In stages such as l, the contact between the first cam roller 42 and the first cam surface 36 provides a large leverage ratio, reducing the operating force, and the load after the final stage of cutting becomes extremely small. (In the feeding stage from C1 to (d), a small lever ratio is given, so the amount of operation of the second lever 14 required to cross both blade parts 18 is small, and the overall operation stroke is shortened. It will be done.

This behavior can be controlled by the relative operating angle α of the second lever 14.
Looking at the relationship between the movement angle β of the blade portion 18 and the movement angle β of the blade portion 18, for example, as one specific data is shown in FIG. 61.5°, (b) force) et al. (C) stage 20
．． 5 degrees, and further (from C1 to (dl), corresponding to the relative rotation at an operating angle α of 10 degrees, both blade parts 18 have rotation angles of 16.2 degrees, 6 degrees, and 7 degrees, respectively. A moving angle β is given, and when α/β is calculated, it is understood that the angular ratio becomes smaller in the stages after (C).

In addition, when opening the two blade parts 18 after cutting is completed, if the second lever 14 is relatively rotated counterclockwise in the figure from the state shown in FIG. 11(A), The first lever 12 is rotated clockwise by the contact between the first cam roller 42 and the return cam surface 46, and when the stage shown in (B) is reached, the return cam roller 50 comes into contact with the return cam surface 48. By these abuts,
The first lever 12 is rotated to the state shown in (C), and a sufficient amount of opening is provided between the two blade portions 18.

To give an example of a specific lever ratio in this return process, in the range (A) to (B), the lever ratio is 89 to 73,
In the range from (B) to (C), it becomes 54 to 43, and if we look at this in terms of the relationship between the relative operating angle α of the second lever 14 and the movement angle β of the blade part 18, for example, as shown in FIG. As shown in FIG.
6° and 13°.

As mentioned above, since the overall operating stroke is shortened by reducing the lever ratio after the final stage of cutting, the relative operating angle α of the second lever 14 does not have to be made that large. Also, a sufficient amount of opening can be provided between the two blade parts 18.

Furthermore, in this embodiment, the main body lever 10 can be used with it fixed to a predetermined fixing member via the mounting bracket 30, so cutting work is facilitated, especially when the work is to be carried out continuously. This also improves safety.

Further, each of the two blade portions 18 is a cutter blade 20.
These cutter blades 20 are replaceable, and another blade part 26 is provided line-symmetrically with the blade part 18 with respect to the center hole 22 of the cutter blade 20, so that even if one of the cutter blades is worn out, it cannot be turned over. You can get a new sharpness by using it with a new canter, and even if both blades are worn out, a new canter can be obtained.
It can be replaced with the blade 20, so maintenance and management of the blade part is easy.

Also, a second lever 14 to which operating force for cutting is applied
However, since the blade part 18 is not provided directly but is provided on the first lever 12 that is separated from the second lever 14, cosilica etc. are added to the second lever 14. However, the two cutter blades 20 are maintained in a state with substantially no gap without being affected by the way in which such operating force is applied, and good sharpness can always be obtained.

Although the embodiments of the present invention have been described in detail above, this is literally an illustration, and the present invention can be implemented in other embodiments.

For example, as the cutter blade 20 shown in FIG.
6 can also be used. In this case, when the blade part 18 is worn out, the blade part 26 can be used as a new blade part by inverting it by 180 degrees.

Furthermore, as shown in FIG. 14, the U-shaped cutout blade portion 1
It is also possible to use a cutter blade 20 with the part opposite to 8 and 26 cut out, or it is also possible to use a cutter blade 20 with the center hole 22 shifted as shown in FIG. 15. If you do this, you can install it upside down, but you cannot install it upside down by 180 degrees, so the blade parts 18 and 26
This prevents the cutting edge from being installed in a direction different from the intended direction. In addition, the cutter blade 20
The main lever 10 and the first lever 12 without using
It is also possible to form an integral blade part 18 at each end of the blade.

On the other hand, regarding the cam mechanism, at the stage shown in FIG.
It is also possible to set their positional relationship so that they come into contact with each other, and since the cutting load usually decreases once the (bl) stage is reached, the operating stroke can be even shorter. .

Further, in the above embodiment, the lever ratio was changed in two stages by the first cam surface 36 and the first cam roller 42, and the second cam surface 38 and the second cam roller 44, broadly speaking, in the cutting process. , cam surfaces and cam rollers can be added to change this to three or more stages. In addition, the specific value of the lever ratio at each stage should not be limited to the specific values mentioned above, but should be set appropriately depending on conditions such as the type of workpiece and usage pattern. be.

Furthermore, it is also possible to provide the second lever 14 with first and second cam surfaces, and the first lever 12 with first and second cam rollers. Other cam followers such as set pins or protrusions may also be employed.

In addition, although specific explanations are omitted, it is of course possible to implement the present invention with various modifications and improvements based on the knowledge of those skilled in the art, as long as they do not depart from the spirit of the present invention. However, the present invention includes these various embodiments.

As described in detail above, the present invention provides for attaching the first lever to the main body so as to be relatively rotatable around the first axis, and the second lever being rotatable relative to the main body around the second axis. A cam mechanism is installed between the first lever and the second lever that automatically changes the lever ratio according to the cutting operation, thereby reducing the operating force by providing a large lever ratio in areas where the cutting load is large. On the other hand, when the load is small, it is possible to provide a small lever ratio and shorten the operating stroke.As a result, the operating force is efficiently transmitted to the cutting section, improving the operability of the cutter. It is played.

[Brief explanation of drawings]

FIG. 1 is a partial front view showing the main parts of a manual cutter that is an embodiment of the present invention, and FIGS. 2 and 3 are a plan view and a left side view of the cutter shown in FIG. 1, respectively. be. Figures 4 and 5 are IV-IV in Figure 2, respectively.
They are a cross-sectional view and a -■ cross-sectional view. 6 is a perspective view of a cutter blade that constitutes the blade portion of the cutter shown in FIG. 1, etc., and FIG. 7 is a cam formation that constitutes the first cam surface of the cutter shown in FIG. It is a perspective view of a member. 8 is a partial front view showing one operating state of the cutter shown in FIG. 1; FIG. 9(a) to 9(d) are operation explanatory diagrams showing the operating state of each stage in the cutting process of the cutter shown in FIG. FIG. 3 is a simple explanatory diagram showing the relationship between the relative operating angle of the blade and the engagement angle of the blade. 1st
1 (A) to (C) are operation explanatory diagrams showing the operating state of each stage in the return process of the cutter shown in FIG. 1 etc., and FIG. FIG. 2 is an explanatory diagram that briefly shows the relationship between the operating angle and the movement angle of the blade portion. FIGS. 13 to 15 are front views showing different embodiments of the canter blade. 10: Main body lever (main body) 12: First lever 14:
Second lever 16: 1st axis ol; axial center of the 1st axis (first axis) 18: Blade section 20: cutter blade (blade section forming member) 28: 2nd axis 02: axial center of the 2nd axis (1st axis) 34: Mounting bracket 36: First cam surface 38: Second cam surface 42: First cam roller 44: Second cam roller 46.487 Return cam surface 50: Return cam roller

Claims (5)

[Claims] (1) A main body having a blade at one end; an intermediate part is attached to the main body so as to be relatively rotatable around a first axis, and one end is shorter than the other end across the first axis; a first lever having a blade portion formed at one end thereof that performs a cutting action in cooperation with a blade portion of the main body; and a second axis having an intermediate portion with respect to the main body parallel to the first axis line. The first lever is attached so as to be relatively rotatable around the first lever, and one end is formed shorter than the other end across the second axis, and the one end is brought into contact with the other end of the first lever; a second lever that rotates relative to the main body to rotate the first lever and bring the two blades closer together; the other end of the first lever and one end of the second lever; is provided between the first lever and the second lever to shift the abutment position of the first lever and the second lever to the first axis side in a load reduction area of the cutting part in the process of bringing the two blade parts closer together. A manual cutter characterized by including a cam mechanism that reduces the lever ratio. (2) A first cam surface and a second cam surface are provided at the other end of the first lever, and a first cam roller and a second cam roller are provided at one end of the second lever, and the two blade sections In the process of approaching the first cam roller, the first cam roller is brought into contact with the first cam surface, and then the second cam roller is brought into contact with the second cam surface one after another at a position closer to the first axis than the contact position. The cutter according to claim 1, wherein the cam mechanism includes the first and second cam surfaces and the first and second cam rollers, which are brought into contact with each other. (3) The cam mechanism also includes a return cam surface and a return cam roller that rotate the first lever relative to the main body in a direction that separates the two blade parts, and the return cam surface is configured to rotate the first lever relative to the main body. 3. The cutter according to claim 1, wherein the return cam roller is provided on one lever and the return cam roller is provided on the second lever. (4) The two blade parts are each formed in a blade forming member that is removably fixed to the main body and the first lever, and the opposing cutting edges of the two blade parts are
The cutter according to any one of claims 1 to 3, wherein the cutter is inclined with respect to a straight line perpendicular to the first axis in a direction closing from the tip side during cutting. (5) The main body is a lever-shaped longitudinal member, and can be used in a portable state by forming a pair of handles together with the second lever, and the main body has a mounting bracket and can be used in a predetermined manner. The cutter according to any one of claims 1 to 4, which can also be used while being fixed to a fixed member.