JPH048407Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a film winding mechanism for a camera or a film holder, and particularly to a film winding mechanism that is optimal for winding a roll film without perforation.

[Conventional technology]

Conventionally, as a winding mechanism for roll film without perforation, for example,
As shown in Japanese Patent No. 27956, the amount of movement of the film due to winding is detected by the rotation of a friction roller, an indexing plate is rotated, and a winding stop lever falls into a concave groove of this indexing plate. The pawl portion of this wind stop lever engages with ratchet teeth integral with the winding shaft to stop rotation.

[Problem that the invention attempts to solve]

However, in such a conventional film winding mechanism, a certain amount of space is required between the wind stop lever and the ratchet teeth when winding the film, and the pitch of the ratchet teeth is also extremely high in terms of strength. It was impossible to make it smaller.

Therefore, even if the wind stop lever faces the groove in the index plate, it will still take some time before it falls into the groove, the wind stop lever locks the ratchet teeth, and film winding stops. This results in a time-consuming process, and if the winding speed of the film is high, the film will stop at a position considerably beyond the predetermined stopping position due to slippage of the friction roller and the like.

The winding speed of this film varies greatly depending on the photographer's habits and the situation of the subject, and even within a single film there is usually considerable variation from frame to frame. In cases where slow-winding was alternately switched back and forth, there was a risk that adjacent screens would overlap each other, and in extremely fast-forwarding, the final screen could be missing.

Also, regardless of the presence or absence of perflation,
It is also widely known that when a film is wound too quickly, static electricity is generated due to friction, and the film is exposed to light due to its discharge, resulting in a fatal phenomenon in which important photographs are lost.

The object of this invention is to provide a film winding mechanism that can solve these conventional problems.

[Means for solving problems]

Therefore, in the film winding mechanism according to this invention, a driving member is moved in only one direction through a one-way clutch to a winding member that rotates by one integer, and a driven member is moved by this driving member through a spring member. I'm trying to rotate it.

A film winding shaft is connected to this driven member, and the rotation of this driven member is regulated by a rotation control mechanism to maintain a predetermined rotational speed, and the driven member is always locked by a locking lever. However, at the end of the rotation of the hoisting member, the lock is released and the driven member is rotated to the stop position of the driving member.

[Effect]

With the above configuration, when the hoisting member is hoisted up, the driving member rotates in the same direction via the one-way clutch, but the driven member is held in a stopped state by being locked by the locking lever. Therefore, the spring member engaged between the two is in a stored state.

Next, when the hoisting member reaches its final stage of rotation, the restraint of the driven member by the locking lever is released, and the driven member rotates to the rotational position of the driving member while its rotational speed is regulated by the rotation control mechanism. In conjunction with this, the film winding shaft rotates and the film is wound at a predetermined speed.

In this case, regardless of the winding speed of the winding member, the film winding speed is a constant speed determined only by the biasing force of the spring and the braking force of the rotation control mechanism.

〔Example〕

Embodiments of this invention will be described below with reference to FIGS. 1 to 3 of the accompanying drawings.

As shown in the figure, a lever 3 is integrally fixed to a hoisting lever 1, which is a hoisting member, via a shaft 2, and a feed pawl 5 is pivotally attached to a shaft 4 on the lever 3, and a spring 6 is used to connect the feed pawl 5. is biased in the left rotation direction.

Further, a barrel 7 as a driving member and a driven disc 8 as a driven member are loosely fitted to the shaft 2 so as to be freely rotatable, and a coil spring 9 as a spring member applying initial tension is secured between them. The driven disk 8 is urged counterclockwise.

Further, a ratchet gear 10 that engages with the feed pawl 5 is fixed on the upper surface of the barrel 7, and the feed pawl 5 and the ratchet gear 10 constitute a one-way clutch, and the clutch is symmetrical with respect to the axis 2 on the side of the barrel 7. 2 in position
Correspondingly, two protrusions 8a, 8b are integrally provided on the driven disk 8 side at symmetrical positions with respect to the axis 2.

A driven gear 11 is fixed to the lower surface of the driven disc 8, and this driven gear 11 is connected via intermediate gears 12 and 13 to a winding gear 15 integrated with a film winding shaft 14. A well-known rotation control mechanism 20, usually called a governor, is composed of an escape wheel 18 and an pallet wheel 19 via gears 16 and 17.
is connected to.

Further, the detent pawl 22 of the ratchet gear 10 is pivotally connected to the shaft 21 and biased in the counterclockwise direction by the spring 23.
A locking lever 24 that can be engaged and detached is pivotally connected to a spring 25.
A pin 26 having a semi-circular cross section at the top is hung from the free end of the locking lever 24 so that it can be engaged with and disengaged from the protrusions 7a and 7b of the barrel 7. .

In addition, in FIG. 2, 27 and 28 are stopper pins that restrict the rotation angle of the lever 3 and the hoisting lever 1, which is integrated with the lever 3 via the shaft 2, to 180 degrees;
29 is a stopper pin that restricts the movement of the locking lever 26.

Next, the operation of this embodiment configured as described above will be explained.

When the winding lever 1 is rotated counterclockwise, the lever 3 simultaneously rotates via the shaft 2, and the feed pawl 5
drives the ratchet gear 10 to rotate the barrel 7 in the same direction, but since the protrusion 8b of the driven disc 8 is locked to the locking lever 24, the coil spring 9 is energized.

When barrel 7 rotates nearly 180 degrees counterclockwise,
Since the arcuate portion of the protrusion 7a engages with the pin 26 and is driven to the right in the figure, the locking lever 24 is rotated to the left against the force of the spring 25 to the position shown by the imaginary line in FIG.

As a result, the protrusion 8b is unlocked, and the driven disc 8 is rotated counterclockwise by the stored force of the coil spring 9, and is wound up via the driven gear 11 and intermediate gears 12 and 13. The film is wound by rotating the gear 15 and the film winding shaft 14 integral therewith counterclockwise.

At this time, since the driven gear 11 is connected to the rotation control mechanism 20 via the intermediate gears 16 and 17,
The rotation speed of the film winding shaft 14 is always controlled to a constant slow speed regardless of the winding speed of the winding lever 1.

Immediately after the protrusion 7a drives the pin 26 and the locking lever 24 releases the driven disk 8, the protrusion 7a
Since the engagement with the pin 26 is disengaged, the locking lever 2
4 is immediately returned to the position shown by the solid line in FIGS. 1 and 2 by the biasing force of the spring 25, and the driven disc 8
When the protrusion 8a is rotated 180 degrees, the protrusion 8a comes into contact with the locking lever 25 and its rotation is stopped.

When the pin 26 separates from the protrusion 7a, the lever 3
comes into contact with the stopper pin 28 and rotation is prevented,
The hoisting lever 1 is returned to its original position by a restoring force (not shown), but the ratchet gear 10 engages with the detent pawl 2.
2 prevents the barrel from rotating in the opposite direction, the barrel 7 is kept in a stopped state without rotating in the opposite direction.

In this state, the protrusions 7a, 8a are changed from the initial state.
, and the protrusions 7b and 8b are simply replaced, and the next hoisting operation returns to the illustrated state.

The rotation angle of the film winding shaft 14 varies depending on the winding diameter of the film, but after the film has been fed a predetermined length, a well-known clutch mechanism (not shown) rotates the driven gear 11 and the winding gear. The connection with 15 is cut off and winding of the film is stopped.

In addition, in the above embodiment, the rotation angle of the hoisting member is
Although we have explained the case of 180 degrees, that is, 1/2 rotation, it is sufficient to make one rotation by an integer, such as 1/3 rotation, 1/4 rotation, or 1 rotation (if the hoisting member is a crank). In such a case, the protrusions of the barrel 7 and the driven disc 8 may be provided at positions equally divided by an integer of the circumference.

Furthermore, in addition to the above-mentioned rotation control mechanisms that regulate the rotational speed of the hoisting gear train, there are also those that consist only of a speed increasing gear train, those that have a wind turbine installed at the final stage of the speed increasing gear train, and those that use an air damper. There is no problem with anything.

Furthermore, this invention can be used not only for rolled films without perforation, but also for films with perforation such as 35mm film and 70mm film, to prevent the generation of static electricity due to premature winding. Extremely effective.

[Effect of idea]

As described above, according to the film winding mechanism of this invention, the film winding speed is always controlled to a constant speed regardless of the winding speed of the winding member, so that the film winding It is possible to effectively prevent screen chipping, etc.

At the same time, there is no risk that the film will be exposed to light due to static electricity being discharged due to fast winding, thereby ruining valuable shots.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of this invention, and FIG. 2 is a plan view showing only the main parts.
FIG. 3 is a sectional view taken along the - line of FIG. 2. 1... Winding lever (winding member), 7... Barrel box (driving member), 8... Driven disk (driven member), 9...
... Coil spring (spring member), 14 ... Film winding shaft, 20 ... Rotation control mechanism, 24 ... Locking lever.

Claims (1)

[Scope of utility model registration request] A drive member connected via a one-way clutch to a winding member that rotates by an integer, a driven member that rotates as a result of the driving member via a spring member, and a film winding shaft connected to the driven member. and a rotation control mechanism that regulates the rotation of the driven member to a predetermined rotational speed, and a locking lever that locks the driven member at all times and releases the lock at the end of rotation of the hoisting member. A film winding mechanism featuring: