JP2921628B2 - Tachograph recording mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tachograph recording mechanism for recording an operation state of a vehicle or the like.

[0002]

2. Description of the Related Art Conventionally, tachographs (operation recorders) have been known in which various data during the operation of a vehicle are recorded in multiple stages on chart paper and used for operation management. FIG.
FIG. 2 shows a tachograph recording mechanism of this kind. The recording mechanism has two recording hands A and B for performing two kinds of recordings, and these recording hands A and B are attached to recording levers A and B, respectively. Also,
The recording mechanism has one motor 61 as a driving source, and the motor 61 has two sets of gear trains (gear trains) 6.
2 and 63 are engaged, and each gear train 62 and 6
Eccentric cams 64 and 65 are engaged with the final stage of No. 3, respectively.

The eccentric cams 64 and 65 are in contact with the recording levers A and B, respectively.
When 4,65 rotates, the recording lever A which is biased in one direction by a spring 66 and 67, B is the rotation shaft O _A, O _B
It is configured to swing around. Note that 68,
69 is performed by changing the position of the recording lever A, a switching device for regulating the swing range of the B, and operates the step-switching 68 _a, 69 _a stopper 68 _b, 69 _b.

[0004] which is configured as described above, when the motor 61 rotates, the eccentric cam 64 and 65 are rotated via the respective gear train 62, thereby recording the lever A, B are rotation axis O _A , swings around the O _B. Along with this, the recording needles A and B which are in contact with the chart paper are driven, and two-stage recording of recordings A and B is performed as shown in FIG.

However, when the two recording levers A and B are used for the two-step recording of the recordings A and B, the recording levers A and B swing, respectively. This requires a large space, and the recording surface of the chart paper cannot be fully utilized. Further, since the recording needles A and B are always in contact with the chart paper, meaningless lines are drawn as shown by C in FIG. 13 even when the recording mechanism is not operating. Furthermore, since the recordings A and B are always stepwise recordings, there is much waste such as generation of chart powder, and if the recording width or position is to be changed, most of the parts need to be changed. Does not have universality to accommodate various tachographs.

In order to solve this problem, Japanese Patent Publication No.
Various types of recording mechanisms have been proposed in Japanese Patent Publication No. 30464, Japanese Patent Publication No. 51-11937, Japanese Patent Application Laid-Open No. 1-285816, and Japanese Patent Application Laid-Open No. 59-65718. In each case, one recording member attempts to record at an arbitrary position with an arbitrary recording width. For example, the one proposed in FIG.
When the motor 81 is rotated, the rotational force slides the recording slide 84 to which the recording needle 83 is attached via the guide plate 82, and moves the position of the recording needle 83 in the radial direction of the chart paper 85 as shown in FIG. It is designed to be moved. An electromagnet M is attached to the recording arm 86 to which the recording needle 83 is fixed. When the electromagnet M is activated, the recording arm 86 rotates around the fulcrum, and the tip of the recording needle 83 It is configured to be able to contact the surface and record at an arbitrary position with an arbitrary recording width.

However, this recording mechanism uses the motor 81 to drive the recording needle 83 in the radial direction of the chart paper 85 and uses the electromagnet M to drive the recording needle 83 in contact with the chart paper 85 in the vertical direction. And so on
Since a separate drive source is required, not only the manufacturing cost is increased, but also because the drive source (electromagnet M) is mounted on the guide plate 82, a large drive torque in the radial direction is required and power consumption is large. Becomes

Further, when the recording needle 83 is brought into contact with the chart paper 85, the recording arm 86 is rotated to perform this operation. Therefore, when the thickness of the chart paper 85 changes (for example, 7 sheets for 7 days), This causes a time lag on recording. This time lag is caused by the rotation center of the chart paper 85 and the recording arm 86.
This amount is generated based on the fact that the center of rotation does not coincide with the center of rotation. As shown in FIG. 15A, this amount increases as the length of the recording arm 86 is shorter and as the rotation angle is larger. Become.

In order to keep the stylus pressure constant with respect to a change in the thickness of the chart paper 85, as shown in FIG. 15B, when the recording needle 83 is supported by a spring 91,
Horizontal stripes remain on the time axis (rotation direction) of the chart paper 85.
This point will be further described with reference to FIG. 15C. The recording arm 86 that rotates around the center of rotation contacts the chart paper 85 at the point a at first. However, it is necessary to secure the stylus pressure necessary for drawing the recording. Needs to be rotated further. Therefore, assuming that there is no chart paper 85, the tip of the needle is rotated to the point c. In fact, the spring 91 bends due to the presence of the chart paper 85, and the tip of the needle is located at the point b. Therefore, it can be seen that a horizontal stripe having a length A from the point a to the point b remains on the chart paper 85.

In the above-mentioned apparatus, the recording needle can be driven in two directions of the radial direction and the vertical direction by one driving source, so that the problem of the manufacturing cost can be solved. However, as described above, the recording arm is rotated and the recording needle is pressed against the chart paper with a spring, so that there is a time lag with respect to the change in the thickness of the chart paper. Horizontal lines will also remain.

The above-mentioned configuration enables the recording needle to be driven in two directions of a radial direction and a vertical direction by one driving source,
In addition, since the vertical movement of the recording needle moves up and down, there is no time lag with respect to a change in the thickness of the chart paper, and no horizontal streak remains.

[0012]

However, as shown in FIG. 16, there are three drive modes, namely, (a) raising the recording needle and moving forward, and (b) lowering the recording needle. Reverse recording, (c) When the upper limit is reached, the recording needle is raised to reverse and return to the origin.
In this case, in order to secure the needle pressure of the recording needle, a larger slip torque is required, and a torque for moving the guide plate is also required, so that a large drive source torque is required. In addition, since a torque transmission gear train and a slip torque portion are formed on the guide plate, a large torque is required to slide the guide plate. Is large.

Furthermore, after the movement of the recording needle is temporarily switched to the mode (c), the mode (a)
Since the state is switched to (b), a structure for detecting and switching this state is required. Therefore, the number of parts is large, the structure is complicated, the accuracy is required, and the cost is high and the durability is problematic.

The present invention provides a tachograph recording mechanism which does not cause a time lag on recording or unnecessary horizontal stripes due to a change in the thickness of chart paper, consumes less power, and has a low manufacturing cost. The purpose is.

[0015]

To achieve the above object, a tachograph recording mechanism according to the present invention engages with a drive motor and a rotating shaft of the drive motor to rotate the motor forward / reverse.
A first one-way clutch that operates at the time of reverse rotation, a second one-way clutch that operates at the time of reverse rotation / forward rotation of the motor, a first cam that engages with the first one-way clutch, and the second one-way clutch And a guide plate which is in contact with the first cam, is driven horizontally by the rotation of the cam in the radial direction of the chart paper, and is attached to the guide plate, and the second cam And a recording needle driven in a direction perpendicular to the driving direction of the guide plate.

Further, the tachograph recording mechanism according to the present invention comprises a drive motor, a first one-way clutch which is engaged with a rotation shaft of the drive motor and operates when the motor rotates forward / reverse, and A second one-way clutch that operates during reverse rotation / forward rotation, a first gear train that engages with the first one-way clutch, a second gear train that engages with the second one-way clutch, A guide plate which comes into contact with the first cam engaged with the first gear train and is driven horizontally in the radial direction of the chart paper by rotation of the first cam; and a second plate engaged with the second gear train. A recording needle up / down lever which engages with the cam and drives the recording needle attached to the guide plate in a direction perpendicular to the driving direction of the guide plate by rotation of the second cam. And

Still further, in the recording mechanism for a tachograph according to the present invention, the shape of the recording needle upper / lower lever is formed in a substantially L-shape having a rotation fulcrum at a center portion, and one of the L-shaped levers is provided. When one end is engaged with the recording needle, a spherical roller is arranged at the center of the other L-shaped lever, and the tip is configured as a guide, and when the second cam rotates, the second cam is rotated. At first, the guide portion of the other lever comes into contact with the cam, and at the maximum diameter portion of the cam, the spherical roller comes into contact with the other lever so that the other lever is tangential to the maximum diameter portion of the cam. It is characterized by having.

[0018]

When the drive motor rotates forward / reverse, the first one-way clutch operates to rotate the first cam via the first gear train. For this reason, the guide plate in contact with the cam is driven horizontally in the radial direction of the chart paper. On the other hand, when the drive motor rotates reversely / forward, the second one-way clutch operates to rotate the second cam via the second gear train. For this reason, the recording needle is driven vertically with respect to the guide plate,
Touch the placed chart paper. In this state, when the drive motor rotates forward / reverse, a record is drawn on the chart paper. Thus, when the drive motor rotates in one direction, the guide plate on which the recording needle is attached is driven in the radial direction of the chart paper, and when the drive motor rotates in the other direction, the guide needle contacts the chart paper in the vertical direction. , And two functions are performed by one drive source.

In this case, when the second cam starts to rotate,
The guide portion of the other lever of the recording needle up / down lever first contacts the cam, and when the cam further rotates, the spherical roller arranged at the center of the lever contacts the maximum diameter portion of the cam, thereby causing the cam to rotate. The other lever is tangential to the largest diameter portion of the cam. At this time, the rotation of the cam is stopped, the motor is rotated in reverse, the guide plate is driven horizontally in the radial direction of the chart paper, and the recording needle moves in the same manner. Since the recording needle up / down lever for driving the recording needle also moves horizontally with the guide plate, the recording needle up / down lever moves as the spherical roller rolls on the surface of the cam.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view showing an embodiment of a tachograph recording mechanism according to the present invention. As shown in the figure, a stepper motor 4 is used as a driving source, and a rotating shaft 4a of the stepper motor 4 is meshed with a biaxial gear 13; And the four-shaft gear 15 are meshed with each other. Of these, the trishaft gear 14 further has a heart cam gear A
The one-way clutch bearing 22, which is a first one-way clutch, is fitted inside the heart cam gear A21.

A heart cam shaft 24 whose lower end is supported by the bearing 8 is fitted to the one-way clutch bearing 22. The tip of the heart cam shaft 24 projects from the one-way clutch bearing 22 and further to the gear case 5. A fixed one-way clutch bearing 23 for preventing reverse rotation of the heart cam is penetrated, and a heart cam 12 as a first cam is fixed to a distal end portion thereof. As shown in FIG. 3, the heart cam 12 is in contact with the guide plate 40, and when the motor 4 rotates forward (indicated by a solid arrow in FIG. 1), the heart cam 12 rotates to move the guide plate 40 in the radial direction (R Direction).

As shown in FIG. 1, a heart cam gear B25 is mounted near the lower end of the heart cam shaft 24, and a slit disc gear 27 is engaged with the heart cam gear B25 via an idle gear 26. ing. A slit disk shaft A28 is fitted in the center of the slit disk gear 27, and a slit disk shaft B29 having a notch on the surface is attached to the tip of the slit disk shaft A28. A disk-shaped slit disk A7 is attached to the slit disk shaft B29 using the notch, and a comb-shaped wall portion 7 is formed around the slit disk A7.
a, and two photosensors (photocouplers) A6 are arranged so as to straddle the wall portion 7a.

On the other hand, a five-shaft gear 16 is meshed with the four-shaft gear 15 meshed with the aforementioned two-shaft gear 13, and a second one-way clutch is provided inside the five-shaft gear 16. One-way clutch bearing 17
Is fitted. A five-shaft 18 is fitted to the center of the one-way clutch bearing 17, and a five-shaft gear A19 is attached to the tip of the five-shaft 18. A gear 32 is engaged with the five-axis gear A19 via a six-axis gear 20. The gear 32 is an eccentric cam 9 which is a second cam attached to the shaft 31 of the recording needle raising / lowering mechanism 30. It is fixed to.

The eccentric cam 9 is provided with a lever 1 which is a recording needle vertical lever according to the present invention in a contact state.
A recording member 10 having a recording needle 11 is engaged with the lever 1. When the motor 4 rotates in the reverse direction (indicated by a chain line arrow in FIG. 1), the eccentric cam 9 rotates and the lever 1 is moved.
The recording needle 11 moves up and down via the recording member 10. Also,
A disk-shaped slit disk B2 is attached to one end of a shaft 31 of the recording needle vertical mechanism 30, and one slit is formed in the slit disk B2. Is always detected.

FIG. 2 is an assembly sectional view of the recording mechanism of the tachograph shown in the exploded perspective view of FIG. (A)
Is a front view, (B) is a side view, (C) is a rear view, and (D) is a bottom view. The reference numerals used in FIG.

As shown in FIG. 4, when the drive motor 4 rotates forward, the recording needle 11 moves in the radial direction of the chart paper together with the guide plate 40 as shown in FIG. When the drive motor 4 rotates in the reverse direction, the recording needle 11 moves up and down in the vertical direction as in the mode (b). That is,
When the drive motor 4 rotates in the reverse direction, the recording needle 11 goes down as shown in (1) and the leading end contacts the chart paper. In this state, when the drive motor 4 rotates forward, the recording needle 11 moves as shown in (2). Draw a record on the chart paper. Next, when the drive motor 4 rotates in the reverse direction, the recording needle 11 rises as shown in (3), and subsequently moves as in (4) when the motor 4 rotates in the forward direction. In this case, the detection of the switching position from (2) to (3) and (4) to (1) is performed by the detection signal of the photo sensor A6 shown in FIG. 1, and the switching from (3) to (4) is performed. The detection of the position is performed by the detection signal of the photo sensor B3. In addition,
For the forward rotation and the reverse rotation of the drive motor 4, which rotation direction is to be the forward rotation is determined for convenience, and if one of the rotations is the forward rotation, the other is only the reverse rotation.

Next, a second embodiment will be described. Note that the same or equivalent parts as those described in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

FIG. 5 is an exploded perspective view of a second embodiment of the tachograph recording mechanism. The difference from the previous embodiment is that firstly, the eccentric cam 36 is fitted into the one-way clutch bearing 17 without directly driving the cam for the rotation of the lever 1 for the vertical repetitive movement of the recording needle 11, The point is that the upper and lower plates 37 are brought into contact with the cam 36 so that the recording needles 11 are repeatedly moved in the vertical direction via the upper and lower plates 37. Second, the magnetic sensor 3 is used to detect the position of the repetitive vertical movement of the recording needle 11.
Third, the third point is that the heart cam shaft 24 is directly connected to the three-wheeled disc A7. Thereby, the number of parts can be reduced as compared with the case of the previous embodiment.

In the second embodiment, the magnetic sensor 35 is used for position detection for position control of drive mode switching (switching of the rotation direction of the motor).
An R sensor, a Hall IC, or the like may be used. In addition, the first
In the second embodiment, a slit machine for position detection,
The position control may be performed by the number of input pulses to the stepper motor 4 without using a photo sensor, a magnetic sensor, or the like, and a servo mechanism using a combination of a DC motor and a potentiometer may be used instead of the stepper motor.

Next, a third embodiment of the present invention will be described. The same or corresponding parts as those described in the first embodiment are denoted by the same reference numerals. This embodiment differs from the first embodiment in the structure of the recording needle up / down lever 1 for moving the recording needle 11 up and down. The lever 1 is shown in FIG.
As shown in the perspective view of FIG. 1, a pivot fulcrum 1a is provided at the center, and a first lever 1b and a second lever 1c extend around the pivot fulcrum 1a. This shape is substantially L-shaped when viewed from the side. A cylindrical projection 1bb is provided on the side surface of the tip end of the first lever 1b corresponding to one lever according to the present invention, and the projection 1bb is engaged with the recording needle 11 via the recording member 10. (See FIG. 1).

The second lever 1c, which corresponds to the other lever of the present invention, is integrated from the rotation fulcrum 1a to the center, and the tip is divided into two parts to form a guide 1cc. Is formed. This guide part 1c
As shown in FIG. 7A, a cylindrical roller shaft 50 having a disk-shaped head 52 fixed at an end is disposed between the roller shafts c. Are rotatably fitted. The other end of the roller shaft 50 is fitted and fixed in the integrated part of the central part of the second lever 1c.

First, as the position of the rotation fulcrum 1a of the second lever 1c and the position where the spherical roller 54 is arranged, the eccentric cam 9
When the diameter of the eccentric cam 9 is smallest due to the rotational position of
When the second lever 1c does not contact the eccentric cam 9,
Of the lever 1c is provided. 7B, the eccentric cam 9 rotates and the spherical roller 54 is positioned at the position of the maximum diameter of the cam 9 as shown in FIG.
Abuts against the surface of the cam 9, and the second lever 1c is mounted at a position where the second lever 1c is tangential to the portion of the cam 9 having the largest diameter.
That is, the spherical roller 54 is arranged at a position where the line connecting the center of the eccentric cam 9 and the place of the maximum diameter intersects the axis of the second lever 1c in the longitudinal direction at right angles.

This is because if the spherical roller 54 is used,
Is disposed at a position far from the rotation fulcrum 1a as shown in FIG. 8A, the maximum rotation angle B of the second lever 1c is changed as shown in FIG. ) Is smaller than the maximum rotation angle A in the state shown in FIG. In order to make B = A, it is necessary to increase the maximum diameter R _{MAX of the} cam, which causes a space problem. In addition, in the case shown in FIG. 8, the eccentric cam 9 and the lever 1c may make unnecessary contact with the lever 1c as shown in FIG. As shown in FIG. 9B, the concave portion 1d
May need to be provided.

On the contrary, the spherical roller 54 is
As shown in (a), if it is arranged at a position far from the rotation fulcrum 1a and the guide portion 1cc is not provided,
By the rotation of the eccentric cam 9, as shown in FIG.
Since the surface of the cam 9 interferes with the head 52 of the roller shaft 50 and the second lever 1c is short, a large rotational torque of the eccentric cam 9 is required. For this reason, the present embodiment is designed as shown in FIG.

Next, the operation of the lever 1 will be described with reference to FIG.
This will be described with reference to (a) to (h). As shown in (a), when the eccentric cam 9 is at the origin, the second lever 1c of the lever 1 is not in contact with the surface of the eccentric cam 9. At this time, although not shown, the first lever 1b is at the top dead center.

When the eccentric cam 9 starts to rotate, the guide portion 1cc of the second lever 1c first contacts the surface of the eccentric cam 9 as shown in FIG. The second lever 1c is pivoted about the pivot 1a. When the eccentric cam 9 further rotates, the spherical roller 54 comes into contact with the surface of the eccentric cam 9 as shown in (d) and (e), and the movement of the spherical roller 54 and the eccentric cam 9 causes the second lever 1 to move.
c continues to rotate.

The state shown in (f), that is, the eccentric cam 9
The rotation of the eccentric cam 9 stops when the line connecting the center of the circle and the point of the maximum diameter and the longitudinal axis of the second lever 1c cross each other at right angles. In this position, the tip of the first lever 1b of the lever 1 is at the bottom dead center, and usually depends on the mounting structure of the recording needle 11, but the recording needle 11 is usually separated from the chart paper. In this state, the guide plate 40 (see FIG. 3) is driven horizontally in the radial direction of the chart paper (vertical direction in the drawing), and the recording needle 11 moves in the same manner. The recording needle 1
The lever 1 that drives the actuator 1 also moves horizontally with the guide plate (FIG. 6).
(In the direction of arrow S shown in FIG. 5), the spherical roller 54 arranged on the second lever 1 c rolls on the surface of the eccentric cam 9. When the guide plate 40 moves to a predetermined position, the eccentric cam 9 again
Rotation starts as shown in (g), and ends as shown in (h). At this time, the recording needle 11 comes into contact with the chart paper.

In this embodiment, the lever 1 can be smoothly rotated by the action of the guide portion 1cc provided on the second lever 1c, and the lever 1 is eccentric. Even if the surface of the cam 9 continues to slide,
The rotation of the spherical roller 54 can prevent the lever 1 and the eccentric cam 9 from being worn. In this embodiment, the guide portion 1 cc is provided at two places with the spherical roller 54 interposed therebetween, but may be provided on only one side.

[0040]

As described above, the tachograph recording mechanism according to the present invention uses one drive motor as a drive source and uses a one-way clutch for power transmission.
The recording needle is moved in the radial direction of the chart paper by the forward or reverse rotation of the motor, and is moved up and down in the vertical direction. No streaks or the like are generated, the power consumption is small, and the manufacturing cost can be reduced.

Also, since the spherical roller is arranged at the center of the recording needle up / down lever and the tip is configured as a guide, when the second cam rotates, the guide of the lever first comes into contact with the cam. , The rotation of the lever is performed smoothly. In addition, since the spherical roller comes into contact with the portion having the maximum diameter of the cam, wear of the cam and the lever due to sliding movement of the lever can be prevented by rotation of the spherical roller.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a recording mechanism of a tachograph according to an embodiment of the present invention.

FIGS. 2A and 2B are assembly sectional views of a tachograph recording mechanism according to an embodiment of the present invention, wherein FIG. 2A is a front view, FIG. 2B is a side view, FIG. 2C is a rear view, and FIG.

FIG. 3 is a diagram illustrating a guide plate, a lever, and the like that are in contact with a heart cam.

FIG. 4 is a diagram showing a movement locus of a recording needle.

FIG. 5 is an exploded perspective view of a second embodiment of the present invention.

FIG. 6 is a perspective view of a main part of a third embodiment of the present invention.

FIG. 7 is a front view of the part shown in FIG. 6;

FIG. 8 is a diagram illustrating a problem when the length from the pivot point of the lever to the spherical roller is long.

FIG. 9 is a diagram for explaining a defect and points to be improved in the case of the structure shown in FIG. 8;

FIG. 10 is a diagram illustrating a problem when the length from the pivot point of the lever to the spherical roller is short.

FIG. 11 is a diagram for explaining the operation of the third embodiment of the present invention.

FIG. 12 is a plan view of a conventional tachograph recording mechanism.

FIG. 13 is a diagram showing a record drawn by the tachograph recording mechanism shown in FIG. 12;

FIG. 14 is a perspective view of a recording mechanism in which the problem of the recording mechanism shown in FIG. 12 is improved.

FIG. 15 is a diagram showing a problem of the recording mechanism shown in FIG. 14;
(A) is a diagram for explaining that the time shift differs depending on the length and the rotation angle of the recording needle, (B) is a diagram in which a spring is attached to the recording needle, and (C) is a horizontal streak remaining on the chart paper by the spring. FIG.

FIG. 16 is a diagram showing a movement trajectory of a recording needle in a conventional tachograph recording mechanism in which one driving source moves the recording needle up and down and moves the chart paper in the radial direction.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Recording needle up / down lever 1a Rotating fulcrum 1b 1st lever 1c 2nd lever 1cc Guide part 4 Drive motor (stepper motor) 9 Eccentric cam 11 Recording needle 12 Heart cam 17 One-way clutch bearing (2nd one-way clutch) 22 One-way Clutch bearing (first one-way clutch) 40 Guide plate 50 Roller shaft 54 Spherical roller

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁶ , DB name) G07C 1/00-15/00 G01D 9/00 G01D 15/32

Claims (3)

(57) [Claims] 1. A drive motor, a first one-way clutch which is engaged with a rotation shaft of the drive motor and operates when the motor rotates forward / reverse, and a second one-way clutch which operates when the motor rotates reverse / forward A one-way clutch, a first cam that engages with the first one-way clutch, a second cam that engages with the second one-way clutch, and abuts on the first cam. A tachograph recording mechanism comprising: a guide plate horizontally driven in the radial direction of the chart paper; and a recording needle attached to the guide plate and driven by the second cam in a direction perpendicular to the drive direction of the guide plate. . 2. A drive motor, a first one-way clutch which engages with a rotation shaft of the drive motor and operates when the motor rotates forward / reverse, and a second one-way clutch which operates when the motor rotates reverse / forward. A one-way clutch; a first gear train engaged with the first one-way clutch; a second gear train engaged with the second one-way clutch; and a first gear train engaged with the first gear train. And a guide plate which is driven in the radial direction of the chart paper by rotation of the first cam, and which engages with the second cam which engages with the second gear train. 2. A tachograph recording mechanism comprising: a recording needle up / down lever for driving a recording needle attached to the guide plate in a direction perpendicular to a driving direction of the guide plate by rotating the cam. 3. The recording needle up / down lever is formed in a substantially L-shape having a rotation fulcrum at the center, and one end of one of the L-shaped levers is engaged with the recording needle. A spherical roller is disposed at the center of the other L-shaped lever, and a tip portion is configured as a guide portion. When the second cam rotates, the second cam first has a guide portion of the other lever. 3. The cam is contacted with the spherical roller at the maximum diameter portion of the cam, and the other lever is tangential to the maximum diameter portion of the cam.
Tachograph recording mechanism as described.