JPH09166153A - Bidirectional torque limiter and electronic information apparatus having it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bidirectional torque limiter to facilitate assembly of individual members easily manufactured and facilitate separation of both torque values from each other. SOLUTION: A bidirectional torque limiter comprises an inner cylinder member 1; an outer cylinder member 2 positioned outside the inner cylinder member 1; a shield member 4 positioned outside the inner cylinder member 1; one or more first coil members 3a wound around the outer surface of the inner cylinder member 1 in a first direction between the outer surface of the inner cylinder member 1 and the inner surface of the outer cylinder member 2; and one or more second coil members 3b wound around the outer surface of the inner cylinder member 1 in a second direction reverse to the first direction between the outer surface of the inner cylinder member 1 and the inner surface of the shield member 4. One end part of the first coil spring member 3a is locked to an outer cylinder member 2 and further, one end part of the second coil spring member 3b is locked to the shield member 4, and bidirectional rotation torque transmitted from the outside to the outer cylinder member 2 through the shield member 4 is limited by a slip between the outer surface of the inner cylinder member 1 and a first coil spring member 3a or a second coil spring member 3b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bidirectional torque limiter that limits load torques associated with rotations transmitted bidirectionally to respective set values or less.

[0002]

2. Description of the Related Art Generally, in a paper feeding device of an electronic information device such as a copying machine, a printer, or a facsimile device, a bidirectional torque limiter is provided in a paper double feeding prevention mechanism to prevent double feeding of paper. At the same time, in the case of a paper jam, the paper feeding mechanism can be reversed to easily remove the jammed paper.

As such a conventional bidirectional torque limiter having a relatively simple structure, there is one disclosed in Japanese Patent Application Laid-Open No. 7-229524. As shown in FIG. 6, the bidirectional torque limiter has an outer cylinder member 2 on the outer side of the inner cylinder member 1.
Is provided, and the coil spring 3 is provided between both cylinders. The coil spring 3 has a right-handed coil portion 3a and a left-handed coil portion 3b, and both coil portions are connected via a bent portion 3c. The inner surface of the outer tubular member 2 is stepped, and a large diameter portion 2a and a small diameter portion 2b are formed. On the outside of the inner tubular member 1, a spring housing tubular portion 1a is provided at a position corresponding to the large diameter portion 2a. A shield member 4 is fitted to the open end of the outer cylinder member 2.

The right-handed coil portion 3a of the coil spring 3 is inserted into the housing tubular portion 1a, and the right-handed coil portion 3a is pressed against the inner diameter surface of the housing tubular portion 1a. In addition, the coil spring 3
The left-handed coil portion 3b is pressed against the inner diameter surface of the small diameter portion 2b of the outer tubular member 2. In the bidirectional torque limiter having such a structure, the maximum torque value that can be transmitted between the inner tubular member 1 and the outer tubular member 2 is the contact pressure between the right-handed coil portion 3a and the inner diameter surface of the storage tubular portion 1a. And the left-handed coil portion 3b and the outer cylinder member 2
It is determined by the contact pressure with the inner diameter surface of the small diameter portion 2b.
Therefore, various torque values can be set by changing the outer diameter of each coil part and the size of the inner diameter corresponding to the coil part.

[0005]

However, in the bidirectional torque limiter having such a structure, the right-handed coil portion 3a and the left-handed coil portion 3b have to be connected via the bent portion 3c, and therefore, normally, the First, the right-handed coil portion 3a is formed by using one coil wire, and then the bent portion 3c.
Since the left-handed coil portion 3b is formed by winding in the opposite direction after forming, in this case, there is no choice but to make the right-handed coil portion 3a and the left-handed coil portion 3b from the same metal material.
It is difficult to make the coil spring constants different for the same number of turns, and therefore it is difficult to obtain bidirectional torque limiters having different set torque values.

Further, when the right-handed coil portion 3a and the left-handed coil portion 3b are formed by using coil wire rods made of different metal materials, not only is there a drawback that a connecting work at the bent portion 3c is required. Also, since a twisting force acts on the bent portion 3c, there is a problem that the connecting portion will be damaged unless the connecting portion is connected so firmly, or even if the connecting portions are made of the same material, unless the material is selected sufficiently. is there.

Further, the storage cylinder portion 1 is provided on the outer surface of the inner cylinder member 1.
The inner cylinder member 1 and the accommodating cylinder part 1a must be formed by accurately fixing a or by cutting out from a round bar made of a metal material. Although this bidirectional torque limiter has a small number of parts, There is also a drawback that the cost cannot be reduced as usual.

The present invention solves such conventional problems and provides a bidirectional torque limiter that can be easily assembled with individual members that can be easily manufactured, and that both torque values can be easily separated. It is intended to be provided.

[0009]

Means for Solving the Problems In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a pipe-shaped inner cylinder member, an outer cylinder member positioned outside the inner cylinder member, and the inner cylinder. A shield member positioned outside the member, and one or more first windings wound between the outer surface of the inner tubular member and the inner surface of the outer tubular member in the first direction between the outer surface of the inner tubular member and the outer surface of the inner tubular member. Between the coil spring member and the outer surface of the inner tubular member and the inner surface of the shield member, one or more first windings wound around the outer surface of the inner tubular member in a second direction opposite to the first direction. Two coil spring members, one end of the first coil spring member is locked to the outer cylinder member, and one end of the second coil spring member is locked to the shield member, Bidirectional rotation torque transmitted from the outside to the outer cylinder member through the shield member A bidirectional torque limiter characterized by being limited by slippage between the outer surface of the inner cylinder member and the first coil spring member or the second coil spring member.

[0010] To solve the above-mentioned problem, the second
According to another aspect of the present invention, there is provided a bidirectional torque limiter according to claim 1, wherein a coil spring constant of the first coil spring member and a coil spring constant of the second coil spring member are different from each other. .

In order to solve the above-mentioned problem, a third
The bidirectional torque limiter according to claim 1, wherein the coil spring constant of the first coil spring member and the coil spring constant of the second coil spring member are substantially the same. It is a thing.

In order to solve the above-mentioned problem, the fourth
According to the invention, the outer diameter of the outer surface portion of the inner tubular member around which the first coil spring member is wound is different from the outer diameter of the outer surface portion of the inner tubular member around which the second coil spring member is wound. A bidirectional torque limiter according to any one of claims 1 to 3 is provided.

In order to solve the above problems, the fifth
The invention according to claim 1 is characterized in that the shield member is locked to a shaft that passes through a space defined by the inner wall of the pipe-shaped inner cylinder member. A bidirectional torque limiter as described is provided.

In order to solve the above problems, the sixth
According to another aspect of the invention, there is provided a bidirectional torque limiter according to any one of claims 1 to 5, wherein a drive mechanism is coupled to the shaft and a reversible driven mechanism is coupled to the outer cylinder member. Electronic information equipment.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 showing a cross section of this bidirectional torque limiter, FIG.
The same symbols as those shown in (A) and (B) indicate corresponding members.

The inner cylinder member 1 is made of a single short metal pipe, and the shaft 5 is inserted through the space defined by the inner wall thereof. The inner diameter of the inner cylinder member 1 is larger than the outer diameter of the shaft 5, and there is a gap between them.

An individual first coil spring member 3 a and second individual coil spring member 3 b are attached to the outer diameter surface of the inner cylinder member 1 so as to apply an appropriate pressing force. Then, if the first coil spring member 3a and the second coil spring member 3b are opposite to each other, that is, if the first coil spring member 3a is right-handed with respect to the hooks 3A and 3B, respectively,
The coil spring member 3b is wound leftward. Of course the reverse is also good. The ends of the coil spring members on the side closer to each other are bent and project at a certain angle with respect to the outer surface of the cylinder defining the outer contour of the coil spring member, and are hooks 3A and 3B, respectively.

The side wall portion 2A, which also functions as a shield plate on one end side of the outer tubular member 2, is smaller than the outer diameter of the other portion of the outer tubular member 2, and is used as a roller of a sheet feeding device such as a copying machine or a printer. In order to make the installation of the stable and easy
It has a rectangular longitudinal section. Further, the side wall portion 2A is the shaft 5
Has a hole 2B for insertion therethrough. The inner diameter surface of the outer cylinder member 2 is stepped, the one end portion of the inner cylinder member 1 is accommodated, and the minimum diameter portion 2C for positioning the inner cylinder member 1 in the longitudinal direction of the shaft 5 is provided. The small diameter portion 2D that also houses the coil spring member 3a, the large diameter portion 2E into which a part of the shield member 4 is fitted, and the groove 2F into which the hook 3A of the first coil spring member 3a is engaged or pressed. Have. The groove 2F connects the first coil spring member 3a and the outer cylinder member 2. The large diameter portion 2E of the outer tubular member 2 is not necessarily required, but the protrusion 4 formed on the outer surface of the shield member 4
An annular groove portion 2E1 that fits with A is formed.

Like the inner diameter surface of the outer cylinder member 2, the other end portion of the inner cylinder member 1 is housed in the inner diameter surface of the shield member 4 to position the inner cylinder member 1 in the longitudinal direction of the shaft 5. A portion 4B to be performed, a portion 4C that also houses the second coil spring member 3b, and a hook 3B of the second coil spring member 3b.
Has a groove 4D that is locked by engagement or press fitting. At one end of the shield member 4, a hole 4E for inserting the shaft 5 and an elongated groove 4F for accommodating the parallel pin 6 for mechanically connecting the shield member 4 and the shaft 5 are provided. Has been formed. Therefore, the bidirectional torque limiter is attached to the shaft 5 by inserting the parallel pin 6 into the small hole 5A of the shaft 5 and fitting the parallel pin 6 into the elongated groove 4F.

Next, the assembly of the bidirectional torque limiter will be described. First, a large number of coil springs are prepared by using the same metal material in the case of setting the same set torque value in both directions, or by using different metal materials in the case of setting different set torque values to each other. By selecting the coil spring member 3a and the second coil spring member 3b, the inner cylinder member 1
Attach it to the outer surface of the machine at a predetermined position in the opposite direction. At this time, if the inner tubular member 1 is attached while being rotated in a direction opposite to the winding direction of the coil spring member, the coil spring member can be easily attached to the inner tubular member 1.

Next, both the first coil spring member 3a and the inner cylinder member 1 are inserted into the outer cylinder member 2 from the left end of the drawing, and the hook 3A of the first coil spring member 3a is locked in the groove 2F. Then, while aligning the groove 4D of the shield member 4 with the position of the hook 3B of the second coil spring member 3b,
The shield member 4 is advanced from the right in the drawing, and the right end of the inner coil member 1 in the drawing together with the second coil spring member 3b is inserted into the shield member 4, and pressure is applied to the annular groove 2E1 of the outer cylinder member 2. The projection 4A of the shield member 4 is fitted. At this time, the hook 3B of the second coil spring member 3b is locked in the groove 4D. In this way, a bidirectional torque limiter that is not disassembled can be easily obtained.

Further, the operation of this bidirectional torque limiter will be described. Here, the first coil spring member 3a is right-handed and the second coil spring member 3b is left-handed when viewed from the direction of the arrow X in the drawing. When the shaft 5 rotates clockwise, the shield member 4 locked to the shaft 5 by the parallel pin 6 also rotates clockwise. Due to the groove 4D and the hook 3B, the second coil spring member 3b locked to the shield member 4 also rotates in the clockwise direction opposite to the winding direction and acts in the direction to increase the winding diameter, but the load torque is If the torque is smaller than the set torque, the inner cylindrical member 1 also rotates clockwise together with the second coil spring member 3b due to the frictional force between the second coil spring member 3b and the inner cylindrical member 1.

Since the first coil spring member 3a is right-handed on the basis of the hook 3A, the clockwise rotation of the inner tubular member 1 causes the inner tubular member 1 to contract in diameter so as to tighten the outer surface of the inner tubular member 1. , The outer cylinder member 2 connected to the first coil spring member 3a by the hook 3A and the groove 2F is rotated in the clockwise direction to transmit the rotational force of the shaft 5 to the outer cylinder member 2.

In this state, if the load torque applied to the outer cylinder member 2 is increased to a set value or more due to a trouble such as paper jam of the paper feed, as described above, the second coil spring member 3b is wound around the coil. Since it rotates in the clockwise direction opposite to the direction, the winding diameter is widened, that is, the diameter is expanded.
The force with which the second coil spring member 3b tightens the outer surface of the inner tubular member 1 becomes small, and slippage occurs between the second coil spring member 3b and the outer surface of the inner tubular member 1. Therefore, when the load torque applied to the outer tubular member 2 increases above the set value, the shield member 4 and the second coil spring member 3b rotate together with the shaft 5, but the inner tubular member 1 and the first coil spring member rotate. 3a and the outer cylinder member 2 do not rotate. As can be seen from this, the load torque value applied to the shaft 5 depends on the frictional force due to the slip between the second coil spring member 3b and the outer surface of the inner tubular member 1, and is limited to the set torque value or less.

Next, when viewed from the direction of the arrow X in the figure, when the shaft 5 rotates counterclockwise, the shield member 4 also rotates counterclockwise, and the second coil spring member 3b also rotates counterclockwise. , The winding diameter is narrowed, and the force for tightening the outer surface of the inner tubular member 1 is strengthened. Therefore, the inner cylinder member 1 rotates counterclockwise together with the second coil spring member 3b regardless of the value of the load torque.

Since the first coil spring member 3a is right-handed, the counterclockwise rotation of the inner cylinder member 1 expands the diameter and weakens the force for tightening the outer surface of the inner cylinder member 1, but the load torque is set. If the torque value is smaller than the torque value, the first coil spring member 3a rotates together with the frictional force acting between the inner tubular member 1 and the first coil spring member 3a, and the outer tubular member 2 moves counterclockwise. Rotate.

In this state, if the load torque applied to the outer cylinder member 2 is increased to a set value or more due to a trouble such as paper jam of the paper feed, as described above, the first coil spring member 3a is wound around it. Since it rotates in the counterclockwise direction opposite to the direction, the winding diameter is expanded, that is, the diameter is expanded,
The force with which the first coil spring member 3a tightens the outer surface of the inner tubular member 1 becomes small, and slippage occurs between the first coil spring member 3a and the outer surface of the inner tubular member 1. Therefore, when the load torque applied to the outer tubular member 2 increases above the set value, the shield member 4 and the inner tubular member 1 rotate together with the shaft 5, but the first coil spring member 3a and the outer tubular member 2 are rotated.
Does not rotate. As can be seen from this, the outer cylinder member 2
The load torque value applied to the shaft 5 by the external force depends on the frictional force due to the slip between the first coil spring member 3a and the outer surface of the inner tubular member 1, and is limited to the set torque value or less.

Therefore, if the pressing force of the first coil spring member 3a and the second coil spring member 3b with respect to the inner cylinder member 1, that is, the tightening force is substantially the same, the bidirectional set torque values are substantially the same. If the first coil spring member 3a and the second coil spring member 3b having different spring constants are formed by using metal wires having different elastic forces, the set torque value can be changed depending on the rotation direction.

FIG. 2 shows a second part of this bidirectional torque limiter.
FIG. 2 is a view showing a cross section of the embodiment of FIG. 1, and the same symbols as in FIG. 1 indicate corresponding members.

This embodiment is different from the embodiment shown in FIG. 1 in that the outer diameter surface of the inner cylinder member 1 is stepped and that the outer cylinder member 2 and the shield member 4 have fitting portions with each other. This means that a simple bidirectional torque limiter having a structure in which the set torque value differs depending on the rotation direction can be obtained.

The inner cylinder member 1 has a first outer diameter portion 1A having substantially the same length and a second outer diameter portion 1B having a diameter slightly smaller than this.
Having. The first coil spring member 3a and the second coil spring member 3b have the same spring constant and the same winding diameter. The first coil spring member 3a and the second coil spring member 3b as described above are respectively connected to the first outer diameter portion 1 of the inner tubular member 1.
When mounted on A and the second outer diameter portion 1B having a diameter slightly smaller than A, the force of the first coil spring member 3a tightening the first outer diameter portion 1A is naturally the second coil spring member 3b. It becomes stronger than the force that tightens the second outer diameter portion 1B.

Therefore, the first coil spring member 3a
The set torque value in the rotation direction opposite to the winding direction of
Is larger than the set torque value in the rotation direction opposite to the winding direction of the coil spring member 3b. Further, although the contact area between the first coil spring member 3a and the first outer diameter portion 1A is small, the contact area between the second coil spring member 3b and the second outer diameter portion 1B is small.
Since it is larger than the contact area with, the set torque value on the side of the first coil spring member 3a is also large from this point.

In this embodiment, since the outer cylinder member 2 and the shield member 4 do not have fitting portions with each other, the hook 3A of the first coil spring member 3a is press-fitted into the groove 2F of the outer cylinder member 2. Is preferred. Although not shown in the figure, the entrance of the groove 2F is slightly smaller than the width of the hook 3A, and the hook 3A can be easily press-fit into the groove 2F by applying a force from the right side of the drawing. The hook 3B of the second coil spring member 3b is engaged with the groove 4D of the shield member 4. Shield member 4 on shaft 5 with parallel pin 6
By stopping, the bidirectional torque limiter does not fall apart due to external force.

FIG. 3 shows a third example of this bidirectional torque limiter.
FIG. 2 is a view showing a cross section of the embodiment of FIG. 1, and the same symbols as in FIG. 1 indicate corresponding members.

This embodiment is different from the embodiment shown in FIG. 1 in that a third coil spring member 3c is added to the side of the first coil spring member 3a, whereby the set torque value is changed depending on the rotation direction. It is possible to obtain a simple bidirectional torque limiter having a different structure.

As shown in FIG. 3, a portion of the inner cylinder member 1 on the side to be inserted into the outer cylinder member 2 is long, and a first coil spring member is formed on an outer diameter surface of the inner cylinder member 1. Three
The third coil spring member 3c is mounted next to a. Inside the outer cylinder member 2, a groove 2F ′ in which the third coil spring member 3c is locked is located at a position different from the position of the groove 2F in which the hook 3A of the first coil spring member 3a is locked. Is formed. Naturally, the groove 2F 'is formed deeper along the inner tubular member 1 than the groove 2F. Therefore, the first coil spring member 3a and the third coil spring member 3c are positioned so that the hooks 3A and 3B are aligned with the grooves 2F ′ and 2F of the outer tubular member 2. In this embodiment, if all three coil spring members are equal, a bidirectional torque limiter with a set torque value of approximately 2 to 1 can be obtained.

FIG. 4 shows a fourth example of this bidirectional torque limiter.
FIG. 2 is a view showing a cross section of the embodiment of FIG. 1, and the same symbols as in FIG. 1 indicate corresponding members.

The main difference of this embodiment from the embodiment shown in FIG. 1 is that the inner cylindrical member 1 is made inexpensive by using a cylindrical round bar having an appropriate outer diameter instead of a pipe shape. Accordingly, the shaft is divided into separate first and second shafts 5 and 5 ', which are fixed to the shield member 4 and the outer cylinder member 2, respectively.

In this embodiment, one end surface of each of the first and second shafts 5 and 5 ′ faces each circular end surface of the inner tubular member 1 with a gap, and the first and second shafts The central axis lines of 5 and 5 ′ and the central axis line of the inner cylinder member 1 are substantially aligned. The outer cylinder member 2 has its end 2
In FIG. 1, except that the second shaft 5 ′ rotates with the outer tubular member 2 because it is locked to the second shaft 5 ′ by the second parallel pin 6 ′ in A. Performs the same operation as the bidirectional torque limiter shown.

Next, FIG. 5 shows a modification of the bidirectional torque limiter shown in FIG. 4, and the same symbols as those in FIGS. 1 and 4 show corresponding members.

The main difference of this embodiment from the embodiment shown in FIG. 4 is that the inner cylinder member 1 has an outer cylinder member 2 and a shield member 4.
In order to fit the inner cylinder member 1 to each other, the inner cylinder member 1 has annular grooves 1C and 1D for fitting, and the outer cylinder member 2 and the shield member 4 are fitted into the annular grooves 1C and 1D, respectively. , 4X (only one is shown in the drawing), the outer cylinder member 2 and the shield member 4 do not have a fitting portion as shown in FIG. 2, and the outer cylinder member One end of 2 is closed, and it does not have a shaft corresponding to the shaft 5'shown in FIG.

In this embodiment, by fitting a plurality of protrusions 2X formed on a part of the inner wall of the outer tubular member 2 into an annular groove 1C formed at one end of the inner tubular member 1, the outer tubular member is formed. 2 does not come off from the inner cylinder member 1. Further, by fitting a plurality of protrusions 4X formed on a part of the inner wall of the shield member 4 into the annular groove 1D formed at the other end of the inner cylinder member 1, the shield member 4 is removed from the inner cylinder member 1. Disappear. Therefore, it is possible to obtain a bidirectional torque limiter that is not disassembled.

At this time, the depth of the annular grooves 1C, 1D is made larger than the height of the protrusions 2X, 4X, and the protrusion 2
X, 4X thickness in the direction of the central axis, that is, width
Since the width is smaller than the widths of C and 1D, the protrusions 2X and 4
Without being disturbed by the engagement between X and the annular grooves 1C, 1D,
The outer cylinder member 2 or the shield member 4 can rotate with respect to the inner cylinder member 1. Also in this embodiment, in order to prevent rotation, the hook 3A of the first coil spring member 3a is in the groove 2F of the outer cylinder member 2, and the hook 3B of the second coil spring member 3b is in the groove 4D of the shield member 4. Be locked. here,
Through hole 2Y of outer cylinder member 2 and through hole 4Y of shield member 4
Is a hole formed due to the relationship of the molds when the projections 2X and 4X are formed in the mold step of pouring a resin material or a metal material into the molds.

In this embodiment, since the bidirectional torque limiter is held in a cantilever state at the tip of the shaft 5, the shaft 5 is preferably fitted into the hole 4E of the shield member 4 and fixed so as not to move. Good to do. Also,
The protrusions 2X, 4X and the annular grooves 1C, 1D are reversed to form a plurality of protrusions at the positions of the annular grooves 1C, 1D of the inner cylinder member 1,
Of course, the annular groove may be formed at the positions of the protrusions 2X and 4X of the outer cylinder member 2 and the shield member 4. Further, the same effect can be obtained by forming a protrusion and a groove or a recess for receiving the protrusion in the central portion of the inner tubular member 1, the outer tubular member 2 and the shield member 4 corresponding thereto.

The various embodiments of the bidirectional torque limiter according to the present invention have been described above.
Inner cylinder member 1, outer cylinder member 2, coil spring member 3 of each embodiment
Alternatively, the shield member 4 may be selected and combined. Further, the number and number of turns of the coil spring member 3 may be arbitrary.

[0046]

As described above, according to the present invention,
Since the coil spring members used are all independent from each other, by combining coil spring members with different spring constants, a bidirectional torque limiter with different set torque values depending on the rotation direction can be easily obtained, and the spring constants are the same. A bidirectional torque limiter having different set torque values depending on the rotation direction can be easily obtained by using three or more coil spring members or by providing a slight step on the outer diameter surface of the inner cylinder. Of course, a bidirectional torque limiter having the same set torque value in both directions can be easily obtained.

Further, according to the present invention, since each member has a simple structure, it can be easily manufactured, and in particular, the required number of coil spring members are attached to the outer surface of the inner tubular member 1, and such an assembly is performed. Since the outer cylinder member 2 and the shield member 4 are separately incorporated in the body, the assembly is extremely easy, and thus an inexpensive bidirectional torque limiter can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of a bidirectional torque limiter according to the present invention.

FIG. 2 is a diagram showing a second embodiment of the bidirectional torque limiter according to the present invention.

FIG. 3 is a diagram showing a third embodiment of the bidirectional torque limiter according to the present invention.

FIG. 4 is a diagram showing a fourth embodiment of the bidirectional torque limiter according to the present invention.

FIG. 5 is a diagram showing a fifth embodiment of the bidirectional torque limiter according to the present invention.

FIG. 6 is a diagram for explaining an example of a conventional bidirectional torque limiter.

[Explanation of symbols]

1 ... Inner tubular member 1A, 1B ... 1st outer diameter portion of inner tubular member 1, 2nd outer diameter portion 1C, 1D ... Annular groove of inner tubular member 1 ... ..Outer cylinder member 2A ... Side wall part 2D of outer cylinder member ...
Small diameter part of outer cylinder member 2B ... Hole for shaft insertion 2E ...
Large diameter part 2C of outer cylinder member ... Minimum diameter part 2F of outer cylinder member ...
Grooves of outer cylinder member 2X ... Plural protrusions 3a, 3b, 3c formed inside the outer cylinder member ... First, second, and third coil spring members 3A, 3B, 3C ... ..Hook of each coil spring member ... Shield member 4A ... Protrusion 4D that fits with the annular groove 2E1 of the outer cylinder member .... Hook 3B of the second coil spring member is locked. Or groove to be press-fitted 4E ... Hole for inserting shaft of shield member 4X ... Plural protrusions 5 5 ′ formed inside shield member Shaft 6, 6 ′ ...・ Parallel pins

Claims (6)

[Claims] 1. An inner tubular member, an outer tubular member located outside the inner tubular member, a shield member located outside the inner tubular member, an outer surface of the inner tubular member and an inner surface of the outer tubular member. And one or more first coil spring members wound in the first direction on the outer surface of the inner tubular member, and between the outer surface of the inner tubular member and the inner surface of the shield member, It comprises one or more second coil spring members wound in a second direction opposite to the first direction on the outer surface of the inner cylinder member, and one end portion of the first coil spring member is the outer cylinder. The second coil spring member has one end thereof locked to the shield member, and bidirectional rotational torque transmitted from the outside to the outer cylinder member through the shield member is applied to the inner cylinder. The outer surface of the member and the first coil spring member or the second coil spring member A bidirectional torque limiter characterized by being limited by slippage between and. 2. The bidirectional torque limiter according to claim 1, wherein a coil spring constant of the first coil spring member and a coil spring constant of the second coil spring member are different from each other. 3. The bidirectional torque limiter according to claim 1, wherein a coil spring constant of the first coil spring member and a coil spring constant of the second coil spring member are substantially the same. 4. The outer diameter of the outer surface portion of the inner cylinder member around which the first coil spring member is wound is different from the outer diameter of the outer surface portion of the inner cylinder member around which the second coil spring member is wound. The bidirectional torque limiter according to any one of claims 1 to 3, characterized in that. 5. The shaft is locked to the shield member so that the center axis of the inner cylinder member and the center axis of the shaft are substantially aligned with each other, and the shaft is locked to the shield member. Bidirectional torque limiter described in. 6. A drive mechanism is coupled to the shaft,
An electronic information device comprising a bidirectional torque limiter according to any one of claims 1 to 5, wherein a driven mechanism is coupled to the outer cylinder member.