JPH0631457Y2 - Film winding and rewinding mechanism - Google Patents

Description

TECHNICAL FIELD The present invention relates to a film winding / rewinding mechanism, and more particularly to a safety device for preventing the film winding from becoming impossible.

"Prior Art and Its Problems" First, a conventional film winding / rewinding mechanism and its problems will be described with reference to Figs. The spool shaft 11 and the rewinding shaft 12 are located at both ends of the camera body, and
The rewinding fork 13 provided at 2 meshes with the patrone key in the patrone 14 when the film is loaded. A film is wrapped around the Patrone key and the inner end of the film is adhered.

An unillustrated winding and rewinding motor is built in the spool shaft 11, and the spool shaft 1 is rotated by the forward and reverse rotations of the motor.
1 rotates in the reverse direction. The rotation of the spool shaft 11 is transmitted to the sun gear 15a via the gear train 15. A swing lever 16 that is frictionally engaged with the sun gear 15a is pivotally mounted coaxially, and a planet gear 17 is pivotally mounted at the tip of the swing lever 16. The rocking lever 16 rocks in the same direction as the rotation direction of the sun gear 15 a, and the planet gear 17 at the tip thereof moves in accordance with the rocking direction of the rocking lever 16.
Selectively mesh with the rewind shaft 12 or the sprocket 18. The spool shaft 11 and the rewinding shaft 12 have gears integrally with each other, and the gear train 15 (sun gear 15a) meshes with these gears.

In the winding and rewinding mechanism described above, when the film is wound, the spool shaft 11 and the gear train interlocked with the spool shaft 11 rotate in the direction shown by the arrow in FIG. Then, the rocking lever 16 rocks toward the sprocket 18 side, and the planet gears 17 move to the sprocket 1 side.
8, the sprocket 18 pulls out the film F from the cartridge 14, and the spool shaft 11 winds it up. At this time, the planet gear 17 does not mesh with the rewind shaft 12, so the rewind shaft 12 is pulled by the film and rotates.

At the time of rewinding, the spool shaft 11 rotates in the reverse direction. Then, each gear rotates as shown in FIG. 5, and the swing lever 16 moves the rewind shaft 1
Swing to the 2 side. Therefore, the planetary gear 17 disengages from the sprocket 18 and meshes with the rewind shaft 12, and the rewind shaft 12 rotates in the rewind direction. Since the spool shaft 11 is rotating in the rewinding direction, the film is rewound into the patrone 14 by the patrone key meshing with the rewinding fork 13.

Thus, the hoisting and rewinding mechanism described above has no problem in normal operation. However, when a strong impact in a specific direction is applied in the completed winding state and the swing lever 16 swings toward the rewind shaft 12 in the state shown in FIG. 6 and engages with this, the winding becomes impossible. Can occur. The reason is analyzed as follows.

In order to enable the rewinding operation described above, the rewinding shaft 1 is always used.
The relationship of the film winding amount by 2 <the film feeding amount by the spool shaft 11 must be established. Therefore, the film movement amount per unit rotation angle of the planetary gear 17 is the movement amount by the rewinding shaft 12 <the movement amount by the spool shaft 11.

Therefore, assuming that the planetary gear 17 meshes with the rewinding shaft 12 in the winding completion state shown in FIG. 6, when the film F is firmly wound, an unwindable state occurs. Resulting in. That is, when trying to start winding, the rocking lever 16 tries to rotate in the direction away from the rewinding shaft 12 by the rotation of the sun gear 15a. The rewinding shaft 12 pulled in the direction of rotation rotates in the rewinding direction, and the planetary gear 17 is rotated in the direction in which the meshing with the rewinding shaft 12 is deepened and retracted. That is, since the peripheral speed of the rewinding shaft 12> the peripheral speed of the planetary gear 17, the closed loop is formed, and the film winding is stopped.

This inconvenience can be solved in principle by urging the swing lever 16 toward the sprocket 18 side by the tension spring 19 shown by the chain line in FIG. However, in this case, the rotational force of the rocking lever 16 due to friction when the sun gear 15a rotates in the rewinding direction must be larger than the force of the tension spring 19. However, increasing the frictional force to increase the turning force of the rocking lever is not preferable because it causes transmission loss during winding and rewinding, and the spring balance is complicated and requires adjustment. turn into.

"Purpose of Invention" The present invention aims to improve the above problems and to obtain a film winding / rewinding mechanism in which the unwindable state does not occur.

[Summary of the Invention] The present invention relates to a spool shaft; a rewinding shaft; a winding and rewinding drive system for rotating the spool shaft in a film winding direction and a film rewinding direction; and a sun driven by this winding and rewinding drive system. A rocking lever supported coaxially with the gear and rocking in a direction corresponding to the rotation direction of the sun gear; supported by the rocking lever,
In a film winding / rewinding mechanism having a planetary gear interlocking with the winding / rewinding drive system, which meshes with a winding / rewinding shaft only when the winding / rewinding drive system rotates in the film rewinding direction, the planetary gear is coaxial with the planetary gear. An improper meshing prevention member that frictionally engages with the gear and rotates together is provided.When the planetary gear rotates in the film winding direction, the improper meshing prevention member engages with a restricting surface formed on the swing lever. A rotation range restricting claw for restricting the rotation position of the improper meshing preventing member; and a planet when the swing lever swings to the rewinding shaft side in the engaged state of the rotation range restricting claw and the regulation surface. It is characterized in that an improper meshing preventing claw is formed between the gear and the rewind shaft to prevent meshing between the both.

"Embodiment of the Invention" The present invention will be described below with reference to illustrated embodiments. 1 to 4 show an embodiment of the present invention and are shown in FIGS.
The same elements as those of the conventional device in the figure are denoted by the same reference numerals.

The improper meshing prevention member 20, which is a feature of the present invention, is coaxially attached to the shaft 17a of the planetary gear 17 coaxially. The improper engagement preventing member 20 has a plurality of arc-shaped cut-and-raised friction pieces 20b around its shaft hole 20a. The cut-and-raised friction pieces 20b are sandwiched between the swing lever 16 and the planet gear 17. The improper meshing prevention member 20 is pressed against the planetary gear 17 side. Due to this frictional engagement, the improper meshing prevention member 20 moves to the planetary gear 1
Both rotate in the direction of rotation of 7.

The unauthorized engagement prevention member 20 has an unauthorized engagement prevention claw 20c extending parallel to the shaft 17a and a rotation range restricting claw 20d. The rotation range restricting claw 20d corresponds to the rotation (rotation) direction of the swing lever 16 and the planetary gear 17, and the swing range control claw 20d.
The first restricting surface 16a and the second restricting surface 16b are brought into contact with each other to restrict the rotational position of the incorrect meshing preventing member 20.

That is, when the swing lever 16 and the planetary gear 17 rotate (rotate) in the regular rewinding direction shown in FIG. 2, the rotation range restricting claw 20d contacts the second restricting surface 16b, and at this time, the incorrect meshing occurs. The prevention claw 20c opens the meshing surface of the planetary gear 17 with the rewind shaft 12. Further, when the swing lever 16 and the planetary gear 17 rotate (rotate) in the regular winding direction shown in FIG. 3, the rotation range restricting claw 20d abuts the first restricting surface 16a to prevent the incorrect meshing claw. 20c is held at the illegal meshing prevention position. The illegal meshing prevention position means the illegal meshing prevention member 2
When 0 rotates to the side of the rewinding shaft 12 while maintaining the relative relationship with the swing lever 16, the improper meshing prevention claw 20c enters between the rewinding shaft 12 and the planetary gear 17, and meshes them. This is the position to prevent.

2 and 3, hatched members are stopper surfaces 21 and 22 for restricting both pivoting ends of the swing lever 16 in the winding direction and the rewinding direction, and are provided on the camera body. There is.

Further, in this embodiment, the friction cut-and-raised piece 20b of the improper meshing prevention member 20 is used as the swinging force of the swinging lever 16. That is, in order to swing the swing lever 16 in the direction corresponding to the rotation direction of the sun gear 15a, a frictional force may be applied between the sun gear 15a and the swing lever 16. However, as in this embodiment, by the friction cutting and raising piece 20b,
Even if a frictional force is applied between the planetary gear 17 and the rocking lever 16, the rocking lever 16 can be rocked in a direction corresponding to the rotation direction of the sun gear 15a, and the number of parts can be reduced. The structure can be simplified.

In the present apparatus having the above-described configuration, in the normal rewinding state and the winding state corresponding to FIGS. 5 and 6, as shown in FIG. 2 and FIG. It has no effect.

On the other hand, when the swing lever 16 and the planetary gear 17 rotate toward the rewinding shaft 12 due to an impact in the winding completion state of FIG. 3, the illegal meshing prevention claw 20c of the illegal meshing prevention member 20 causes the planetary gear 17 to move. Of the rewinding shaft 12 is prevented. This state is shown in FIG.

That is, in the state shown in FIG.
The rotation range restricting claw 20d is in a position where it comes into contact with the first restricting surface 16a of the swing lever 16, and the improper meshing preventing claw 20c is in the improper meshing preventing position at this time. As described above, the improper meshing prevention position means that when the improper meshing preventive member 20 is rotated toward the rewinding shaft 12 while maintaining the relative relationship with the swing lever 16, the improper meshing preventing claw 20c is rewound. 12 and the planetary gear 17 are located so as to prevent the two from meshing with each other. Rotation of the rocking lever 16 due to a shock from the state of FIG. 3 to the state of FIG. Since the rotation is such that the relative relationship between the swing lever 16 and the incorrect meshing prevention member 20 is not changed, meshing with the planetary gear 17 rewind shaft 12 is prevented. Therefore, hoisting is started next and the sun gear 15
When a rotates in the direction of the arrow in FIG. 1, the swing lever 16 rotates to the sprocket 18 side without any trouble, and the planetary gear 1
7 meshes with sprocket 18. Therefore, the unwindable state does not occur.

In the above embodiment, the present invention has been described as a type in which a drive system motor for rotating the spool shaft 11 in the winding direction and the rewinding direction is built in the spool shaft 11, but the drive system motor is Any gear of the gear train 15 may be rotated. Further, although the above is the type having the sprocket 18, the present invention can be applied to the type not having the sprocket 18 for controlling the winding amount by the rotation angle of the spool shaft 11.
In this case, the planetary gear 17 meshes with the rewinding shaft 12 only when rewinding, and is separated from the rewinding shaft 12 when hoisting.

[Advantage of Invention] As described above, according to the present invention, even if a strong impact in a specific direction is applied in the completed winding state and the swing lever swings to the rewind shaft side, the improper meshing prevention member prevents the planet from moving. The mesh between the gear and the rewind shaft is prevented. Therefore, the situation of unwinding does not occur, and it is possible to provide a more inexpensive and reliable hoisting and rewinding mechanism.

[Brief description of drawings]

FIG. 1 shows an embodiment of a film winding and rewinding mechanism according to the present invention. FIG. 1 is a plan view of an essential portion in an improper meshing prevention state, and FIGS. A plan view of
FIG. 4 is an exploded perspective view of the main part, and FIGS. 5 and 6 are plan views of a conventional film winding and rewinding mechanism in a rewinding state and a winding state. 11 ... Spool shaft, 12 ... Rewinding shaft, 13 ... Rewinding fork, 14 ... Patrone, 15 ... Gear train, 15a
...... Sun gear, 16 ...... Rotating lever, 16a …… First regulation surface, 16b …… Second regulation surface, 17 …… Planetary gear, 18
...... Sprocket, 20 …… Unauthorized meshing prevention member, 20a
...... Shaft hole, 20b ...... Cut-and-raised friction piece, 20c ...... Rotation range control claw, 20d ...... Incorrect meshing prevention claw.

Claims (1)

[Scope of utility model registration request] 1. A spool shaft; a rewinding shaft; a winding rewinding drive system for rotating the spool shaft in a film winding direction and a film rewinding direction; coaxial with a sun gear driven by this winding rewinding drive system. A swing lever supported and swinging in a direction corresponding to the rotation direction of the sun gear; supported by this swing lever and meshed with a rewinding shaft only when the winding and rewinding drive system rotates in the film rewinding direction A film winding / rewinding mechanism having a planetary gear that is interlocked with the winding / rewinding drive system, wherein an improper meshing preventive member that is frictionally engaged with the planetary gear and rotates together is provided coaxially with the planetary gear, When the planetary gear rotates in the film winding direction, the improper meshing preventive member engages with a restricting surface formed on the swing lever to regulate the rotational position of the improper meshing preventive member. Claw and; this rotation range control claw When the swing lever swings to the rewind shaft side in the engagement state between the and the regulation surface, an improper meshing prevention claw that is positioned between the planetary gear and the rewind shaft to prevent the meshing between the two is provided. A film winding and rewinding mechanism characterized by being formed.