JPS59143845A - Film take-up device - Google Patents

Abstract

PURPOSE:To maintain always a constant film take-up amount in a long film take-up device of a cinecamera by reducing automatically the rotational speed of a variable speed disk integral with a take-up shaft as the film take-up amount is increased. CONSTITUTION:When a drive shaft 2 is rotated through gears 1a, 2a by a motor 1, the rotation is then transmitted to a variable speed disk 5 through steel balls 4, 4 to rotate a spool 13 through a take-up shaft 9 integral with said disk 5 and a slip ring 14 for taking up a film F. As the film take-up amount is increased, a detecting lever 16 and a segment lever 18 are pivoted in the direction 16b through a contact roller 15 contacting the outer periphery of the film F. Then, a slide bed 6 moves in the direction 6a along a guide rod 7 through a gear 21 and a steel ball 4 contacts the larger diameter position on the variable speed disk 5 so that the rotational speed of the variable speed disk 5, i.e. the take-up shaft 9 will be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a film winding device for a cine camera, and particularly to a winding device for a cine camera using a long film.

- Generally speaking, when the rotational speed of the film winding shaft of the film winding device in a cine camera is constant, the winding rotational speed at the beginning of film winding, that is, when the film winding outer diameter is small, is the same at the end of film winding. In other words, it is also applied when the film winding outer diameter is large, and a difference occurs in the amount of film winding.

Conventionally, film winding devices for cine cameras use only a drive force transmission mechanism that uses frictional force to rotate the film winding shaft in response to changes in the film winding outer diameter. It did not have a mechanism to change and control the number. This conventional device uses a friction transmission mechanism to cause slippage in order to correct the difference in film winding amount.

For this reason, a drive torque greater than that originally required for film winding is required, the drive motor becomes unnecessarily large, and the friction area becomes slippery especially when the outside diameter of the film is large in the later stages of winding. This has the disadvantage that winding failure is likely to occur due to severe wear and a decrease in frictional transmission force.

The present invention was proposed in order to solve the above-mentioned drawbacks, and it is possible to reduce the amount of film taken up in the early and late stages of film winding with the minimum driving torque required for film winding and without causing slippage. It is an object of the present invention to provide a film winding device for a cine camera that can eliminate the difference.

Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

FIG. 1 is a plan view of an embodiment of the present invention, and FIG. 2 is a partial sectional view of the embodiment of FIG. The motor 1 is a rotational drive source, and its rotation is transmitted to the drive shaft 2 via a gear la and a gear 2a. The base 3 serves as the base of the winding mechanism. The rotational drive of the drive shaft 2 is transmitted to the speed change disc 5 via the steel balls 4. The sliding table 6 has a substantially rectangular flat plate shape, and guide bars 7, 7 are installed along the longitudinal direction thereof, and the guide rods 7, 7 are fixed to the base 3. The slide table 6 slides along the guide rods 7 in the longitudinal direction of the guide rods 6a or 6b. Since the steel ball 4-4 is rotatably mounted approximately in the center of the slide table 6, when the slide table 6 slides, the steel ball 4-4 is always in contact with the drive shaft 2 and the rotational drive is controlled by the speed change disc 5.
to communicate. This speed change disc 5 is a winding shaft 9 for the film F.
It is fitted concentrically to the lower end of the. The spring 10 is held between the speed change disk 5 and the lower end surface of the thrust bearing 11, and presses the speed change disk 5 against the steel balls 4. Due to this suppression, the rotational drive of the drive shaft 2 is transmitted through the steel balls 4 to the speed change disc 5 without slipping.
transmitted to. The winding shaft 9 is rotatably fitted to the base 3 via a thrust bearing 11 and a bearing 12. The spool I3 and the winding shaft 9 are interlocked by frictional force caused by a slip ring 4 held between them. On the other hand, the contact roller 15 is rotatably supported by one end of the detection lever 16 . The other end of the detection lever 18 is connected to the shaft 17
is rotatably supported by. A door-shaped gear 18 is attached to the shaft 17 so as to rotate 0f in conjunction with the detection lever 1B.

The detection lever 16 and the door-shaped gear 18 are always urged to rotate in the direction of arrow 1.8a by the spring 19 engaged with the spring brackets 19a and +9b, and this urging causes the outer diameter of the contact roller 15 and the film F to be are always in contact with each other. The door-shaped gear 18 and the tooth width 21 mesh with each other, and the gear 21 and the sliding base 6 mesh with each other.
It is configured so that the teeth 6b provided on the side surfaces mesh with each other. The contact roller 15 rotates in the direction of the arrow 16a or 18b in accordance with the outer diameter r corresponding to the amount of winding of the film F, and the detection lever 16 also rotates in conjunction with this.

The slip ring 14 applies a winding pressure (=J) to the film F, and when the number of revolutions of the winding shaft is set so as to wind a few percent more than the prescribed film winding amount, This is to slip and absorb the difference that occurs between the two.

Next, the operation will be explained.

The rotational drive of the motor 1 is transmitted to the drive shaft 2 via the gear 1a5 and the gear 2a, and drives the drive shaft 2 to rotate. The rotational force of the drive shaft 2 is transmitted to the speed change disc 5 via the steel balls 4. Since the variable speed disc 5 is fitted onto the lower end of the winding shaft 9, the winding shaft 9 also rotates in conjunction with the winding shaft 9, and the rotational force is further transmitted through the slip ring 14, causing the spool 13 to rotate. The film F is wound up by this rotation of the spool 13.

Way 1. The contact roller 15, which is always in contact with the outer diameter of the film F, rotates about the shaft 17 in the direction of arrow +6a or IEib in response to the radius r of the film F, which changes in accordance with the amount of winding of the film F. do. In other words, as the film winding amount increases, the outer diameter r increases, and the contact roller 15
rotates in the direction of arrow IBb. When the contact roller I5, that is, the detection lever 16, rotates in the direction of arrow 18b, the door-shaped gear 18, which is integrally fixed with the detection lever 16, also rotates in the direction of arrow 11.
Rotates integrally in direction 3b. This rotation causes gear 21
rotates counterclockwise. The sliding base 6, which is provided with a tooth portion 6b that meshes with the gear 21, slides in the direction of the arrow 6a, which is also the radial direction of the speed change disc 5. The steel ball 4-4 also slides together in the direction of the arrow 6d. Therefore, the contact position between the steel balls 4 and the speed change disc 5 also moves in the direction of the arrow 6a, and the steel ball 4 comes into contact with a position in the outer radial direction of the speed change disc 5. For this reason, rotation is transmitted from the drive shaft 2 to the speed change disc 5 via the steel balls 4, 4, so even if the rotation drive of the drive shaft 2 is constant, the rotation speed of the speed change disc 5, that is, the film F The rotational speed of the winding shaft 9 decreases, and the winding speed of the film F decreases. Therefore, regardless of the size of the outer diameter r of the film F, the winding distance of the film F is constant.

In the present invention, as described above, since the film winding 111 is constant, the torque of the drive source monitor can be kept constant, and stable motor control can be performed.

Furthermore, since the slip means for winding is unstable, only a small torque is required, resulting in the effect that the drive motor can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a plan view of one embodiment of the present invention, and FIG. 2 is a plan view of an embodiment of the present invention.
3 is a partial cross-sectional view of the illustrated embodiment; FIG. ■... Drive source, 12... Sliding table, 4...
Steel ball, 13... Spool, 5... Speed change plate, 14... Slip ring 6... Sliding base, 15... Contact roller, 9... Winding shaft, 1B... Detection lever, 11...Thrust bearing, 18...Door type gear, 21...Gear, F...Film, r...Outer diameter.

Claims (1)

[Scope of Claims] Film winding amount detection means that contacts the outer diameter of the film that changes in accordance with the film winding amount and moves in accordance with the change in the outer shape, and the film winding amount detection means a movement transmitting means for transmitting a first movement of the movement transmitting means; and a movement transmitting means for converting the first movement transmitted by the movement transmitting means into a linear motion in a predetermined direction and rotating a sphere transmitting a second rotation by the drive source. a speed-changing rotating body that contacts the spherical body at a position off the center of rotation and to which the rotation and motion of the drive source is transmitted via the spherical body; and the speed-changing rotating body; A film winding device comprising a winding means for winding the film in conjunction with each other.