JPS589314Y2 - Sheet winding and unwinding mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet winding and rewinding mechanism suitable for use in data input devices and the like, and an object of the present invention is to provide a sheet winding and rewinding mechanism that enables particularly stable operation.

Figures 1 and 2 are used as input devices for electronic computer systems.
As shown in the figure, for example, data such as product name and customer name are written on a strip-shaped sheet 2, and the sheet 2 is first moved forward or backward so that the necessary data appears on the display section 1a of the housing 1. In some cases, a sheet 2 is searched and then a key 3 corresponding to an input item on the searched sheet 2 is pressed to input the input item.

In this type of input device, the sheet 2 is fed by two drums 4 and 5 attached to each end of the sheet 2.
This can be achieved by rotating.

However, in this case, unless the sheet 2 is equally wound on both drums 4 and 5 with the sheet 2 wound thereon, one drum will be larger than the other drum.

Therefore, if the motor is rotated in this state, since the drums 4 and 50 have the same number of rotations but different outer diameters, the amount of winding up and the amount of feeding out will be different, and if the amount of feeding out is greater than the amount of winding up, the sheet 2 will On the other hand, if the amount of winding is greater than the amount of feeding, excessive tension is applied to the sheet 2, which may cause the sheet 2 to break.

In view of the above points, the present invention provides a simple sheet winding and unwinding mechanism capable of correcting the winding amount and the feeding amount. In Figure Vc, 6 is a drive shaft to which a drive drum γ and a flange 8 are fixed.
2 is transmitted to the drive shaft 6 through gears 13,14.

Reference numeral 15 denotes a driven shaft to which a driven drum 16 and a flange 17 are fixed. Like the drive shaft 6, the driven shaft 15 is also rotatably attached to the side wall 10.11 via a bearing 1B.

19 and 20 are sprockets fixed to the drive shaft 6 and the driven shaft 15. Both sprockets 19 and 20 have the same number of teeth, and are connected by a timing belt 21, so that the drive shaft rotates 60 times. The same number of rotations is transmitted to the driven shaft 15Vc.

Reference numeral 2 denotes a belt-shaped sheet made of synthetic paper or the like that is wrapped around the driving drum I and the driven drum 16 at each end, and stretched between both drums 7 and 16. Desired data is written on the surface of the sheet 20. has been done.

In addition, 22... is a connecting rod that connects both side walls 10 and 11.

Therefore, the installation of the driven shaft 15 and the driven drum 16 will be explained with reference to FIG. One end of the spring 23, which is wound at a predetermined interval, is attached to the protrusion 17a of the flange 17.
The other end of the spring 23 is secured to a hole 17b provided in the inner wall of the driven drum 16, and the other end of the spring 23 is engaged with a hole 16a provided in the inner wall of the driven drum 16.

Therefore, the driven shaft 15 is fixed! If the driven drum 16 is rotated in the direction of the arrow, it can rotate against the return force caused by the torsion of the spring 23.

With this configuration, the sheet 2 wound around the driven drum 16 is constantly pulled by the restoring force of the spring 23, so that the sheet 2 does not loosen, and when the amount of winding is greater than the amount of feeding, The difference is that the spring 23 is the driven shaft 15
This is corrected by further twisting.

Analyzing this state using FIG. 5, A in the figure shows a case where the diameter d1 of the driving drum 7 is larger than the diameter d2 of the driven drum 16, and the sheet 2 is wound up by the driving drum I. If the amount of winding is L, the rotation angle θ of the drive drum 1 is as follows: θ=(L/πdl)x360. The rotation angle θ' of the driven drum 16 is expressed as 0' = (L/πd2.) x360, and from these equations, Vθ' == d 2 / d t.

Since dl>d2, θ'-θ>O.

This θ'-θ is the angle at which the spring 23 is further twisted relative to the driven shaft 15.

Generally speaking, the diameter d2 of the driven drum 16 is larger than the diameter dl of the driving drum T, and the sheet 2 is connected to the driven drum 16.
This figure shows the case of winding up the sheet 2. If the feeding amount of the sheet 2 is L, the rotation angle θ of the drive drum I is θ=(L/π
dl) x360, the rotation angle θ' of the driven drum 16 is θ'
=(I4/πdz)x360, and from these equations, θ/θ'=dz==dt.

Since d2'')di, θ-θ'>O, and this θ-θ' is the angle at which the spring 23 is further twisted relative to the driven shaft 16.

As described above, in the present invention, the spring 23 is installed between the flange 1T fixed to the driven shaft 15 and the driven drum 16, so that 150 rotations of the driven shaft can be transmitted to the driven drum 16 through the spring 23. Therefore, the amount of sheet 2 fed by the driving drum I is the same as that of the driven drum 1.
Even if the amount of winding is greater than the amount of winding according to 6, the spring 23
The sheet 2 does not loosen due to the restoring force of The sheet winding/unwinding I has an extremely simple structure and can operate stably, as there is no risk of the sheet 2 being cut due to excessive tension being applied to the sheet 2.
This has a significant practical effect in providing a Jt structure.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the external appearance of the data input device, Fig. 2 is a cross-sectional side view of main parts explaining the inside of the data input device, Figs. 3 is a perspective view of the main part, FIG. 4 is a cross-sectional side view of the main part explaining the inside of the driven drum, and FIG. It is an explanatory diagram. 2... Seat, 6... Drive shaft, 7...
... Drive drum, 15 ... Driven shaft, 16.
...Followed drum, 17...Flange, 2
3... Spring.

Claims (1)

[Scope of utility model registration request] A sheet winding/unwinding device in which each end of the sheet is wound around a driving drum provided on a driving shaft and a driven drum provided on a driven shaft, and the sheet is wound and unwinded by rotation of the driving shaft and driven shaft. A sheet winding mechanism characterized in that a spring is secured between a flange fixed to a driven shaft and a driven drum so that rotation of the driven shaft can be transmitted to the driven drum via the spring. Return mechanism.