JPH0428778Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" The present invention is a paper bail device that guides paper while pressing it against a platen in a typewriter, etc., and in particular, a bail rod with a flat portion by chamfering both sides of the outer circumferential surface. horizontally between the left and right bail arms,
The present invention relates to a paper bail device in which a cylindrical pinch roller is rotatably supported on the outer periphery of the bail rod.

"Prior Art" This type of paper bail device makes the bail rod unrotatable with respect to the bail arm, and
In order to display a scale on the outer circumferential surface of this bail rod, a part of the outer circumferential surface is made flat.

4 and 5 show conventional examples thereof. In the figure, a bail rod 1 is non-rotatably suspended horizontally on rotating left and right bail arms (not shown). This bail rod 1 has a flat portion 2 by chamfering both the front and rear sides of its circular outer peripheral surface.

A plurality of cylindrical pinch rollers 3 are fitted around the outer circumference of the bail rod 1. Each pinch roller 3
has an annular spring groove 4 in the center of its inner peripheral surface.
is formed. An annular spring 5 is fitted into the spring groove 4, and the spring 5 is in pressure contact with the outer peripheral surface of the bail rod 1. Due to this pressure contact, the pinch roller 3 does not accidentally slide in the axial direction of the bail rod 1, but can be forced to slide. Since the spring 5 is annular, the pinch roller 3 can freely rotate relative to the bail rod 1.

"The problem that the invention attempts to solve" However, with this conventional one, the pinch roller 3
When the pinch roller 3 is pressed against the platen 6 by the spring force acting on the bail arm, that is, when in use, the inner peripheral surface of the pinch roller 3 is pressed against the bail rod 1.
Since the pinch roller 3 comes into pressure contact with the corner 7 between the circular part and the flat part of the outer circumferential surface of the pinch roller 3, stress concentrates on this corner 7 and the pinch roller 3 is braked, causing rotational deviation between the pinch roller 3 and the platen 6. There was a problem in that the paper that was fed while being sandwiched between these became wrinkled.

The purpose of the present invention is to provide a paper bail device that not only allows pinch rollers to be rotated easily but also that can press paper securely and can be easily assembled with a small number of parts.

``Means for Solving the Problems'' In the paper bail device of the present invention, a split sleeve is prepared for each pinch roller, and the split sleeve is fitted onto the outer periphery of a chamfered bail rod to assemble. The split sleeve has a pair of resilient bearing ribs that are integrally formed at a base end by a common annular portion and are opposed to each other in parallel.
These bearing ribs have a flat inner surface, a part of which has an integral braking protrusion, an outer circumferential surface that is a perfect circle along the inner circumferential surface of the pinch roller, and the tip of each bearing rib. A retaining protrusion is integrally provided on the outer periphery of each.

The split sleeve is fitted onto the outer periphery of the bail rod, and the braking protrusions on the inner surface of the pair of bearing ribs are brought into pressure contact with the flat surfaces on both sides of the bail rod. It is now possible to slide while receiving braking force. Further, the pinch roller is rotatably fitted to the outer periphery of the pair of bearing ribs between the annular portion and the retaining protrusion.

"Operation" Therefore, the pinch roller smoothly rotates around the circular outer peripheral surface of the split sleeve. By sliding the split sleeve along the bail rod,
The position of the pinch roller can be adjusted.

Further, during assembly, the pair of bearing ribs of the split sleeve are forcibly contracted, and the pinch roller can be easily fitted onto the outer periphery of these bearing ribs. The fitted pinch roller becomes rotatable between the annular portion of the bearing rib and the retaining protrusion, and reliably presses the paper without accidentally coming off. Furthermore, the inner surfaces of the pair of bearing ribs are provided with braking protrusions that press against the flat surfaces on both sides of the bail rod, so that the split sleeve and pinch roller will not accidentally slide against the bail rod. do not have.

``Example'' An example of the present invention will be described below in detail based on the drawings.

As shown in Figures 1 and 2, the bail rod 10
The front and rear sides of the circular outer peripheral surface are chamfered to form front and rear vertical plane parts 11, and a scale 12 is displayed on the front plane part 11. This bail rod 10
is non-rotatably suspended horizontally on the bail arm (not shown) by fitting both ends into holes of the bail arm (not shown). Bailrod 1
A plurality of cylindrical pinch rollers 1 are arranged around the outer circumference of the roller 0.
3 are each supported by a split sleeve 14.

The split sleeve 14 is integrally molded from synthetic resin,
Two long elastic bearing ribs 16 are provided in parallel to one side of the annular portion 15, and short clamping ribs 17 are provided in parallel to the other side. The outer peripheral surface 16a of both bearing ribs 16 is connected to the pinch roller 13.
is a perfect circular surface along the inner circumferential surface 13a of the bail rod 10, while the inner surfaces of both bearing ribs 16, the inner surface of the annular portion 15, and the inner surface of the clamping rib 17 are engaged with the front and rear flat portions 11 of the bail rod 10. The plane is as perpendicular as possible. That is, the split sleeve 14 has front and rear flat parts 18 formed on its inner surface that engage with the front and rear flat parts 11 of the bail rod 10. Further, a retaining protrusion 19 is formed at the tip of the outer peripheral surface of the bearing rib 16, and a braking protrusion 20 is formed on the vertical inner surface of both clamping ribs 17.

Note that the braking protrusion 20 may be formed on the inner surface of the bearing rib 16.

The pinch roller 13 is made of elastic synthetic resin and is integrally molded into a true cylindrical shape. This pinch roller 13 is fitted onto the outer periphery of the split sleeve 14 with both bearing ribs 16 in a contracted state, and then the split sleeve 14 is fitted onto the outer periphery of the bail rod 10. is installed on.

In this installed state, the split sleeve 1
The front and rear braking protrusions 20 of 4 are in pressure contact with the front and rear flat parts 11 of the bail rod 10, and the split sleeve 1
4 does not slide against the bail rod 10 inadvertently, but can be forced to slide manually. Further, the split sleeve 14 cannot rotate relative to the bail rod 10, but the pinch roller 13 is rotatable relative to the split sleeve 14. The outer peripheral surfaces 16a of both bearing ribs 16 of the split sleeve 14 are perfectly circular surfaces along the inner peripheral surface 13a of the split sleeve 14, so that the pinch roller 13 can be attached to the platen 21.
Even if the inner circumferential surface 1 of the pinch roller 13
3a and the outer circumferential surface 16a of the bearing rib 16, and the pinch roller 13
rotates easily around both bearing ribs 16.

"Effects of the Invention" As described above, according to the paper bail device of the present invention, a split sleeve is prepared for each pinch roller, and this split sleeve is fitted around the outer circumference of the bail rod so that it cannot rotate but can slide. Since the pinch roller is rotatably fitted to the circular outer circumferential surface of the split sleeve, local stress is generated between the inner circumferential surface of the pinch roller and the bail rod as in the conventional case, causing stress on the pinch roller. There is no possibility that the rotation will be hindered and the paper will become wrinkled due to rotational misalignment with the platen.

Further, during assembly, the pair of bearing ribs of the split sleeve are forcibly contracted, and the pinch roller can be easily fitted onto the outer periphery of these bearing ribs. The fitted pinch roller becomes rotatable between the annular portion of the bearing rib and the retaining protrusion, and reliably presses the paper without accidentally coming off.

Furthermore, the inner surfaces of the pair of bearing ribs are provided with braking protrusions that press against the flat surfaces on both sides of the bail rod, so that the split sleeve and pinch roller will not accidentally slide against the bail rod. do not have.

In addition, the split sleeve has an annular part and a stopper protrusion that prevent the pinch roller from coming off, and a brake protrusion for the bail rod, so there are only three parts: the bail rod, the split sleeve, and the pinch roller. It is easy to assemble and has a small number of parts, making it economical.

[Brief explanation of the drawing]

Figures 1 to 3 show one embodiment of the present invention, Figure 1 is an exploded perspective view, Figure 2 is a cross-sectional side view, Figure 3 is a plan view, and Figures 4 and 5 are cross-sectional side views of the conventional example. and a longitudinal front view. 10...Bailrod, 11...Plane part, 12
... Scale, 13 ... Pinch roller, 13a ... Inner peripheral surface of pinch roller, 14 ... Split sleeve, 1
5... Annular part, 16... Bearing rib, 16a... Outer peripheral surface of bearing rib, 17... Clamping rib, 18... Flat part, 19... Retaining protrusion, 20... Braking protrusion,
21...Platen.

Claims (1)

[Scope of utility model registration request] In a paper bail device such as a typewriter, in which a bail rod having a flat surface with both sides of its outer peripheral surface chamfered is horizontally suspended between left and right arms, and a plurality of cylindrical pinch rollers are rotatably supported on the outer periphery of the bail rod, A split sleeve is prepared for each of the above-mentioned pinch rollers, and the split sleeve has a pair of resilient bearing ribs whose base end portions are unified by a common annular portion and are opposed to each other in parallel. The bearing rib has a flat inner surface, a part of which has an integral braking protrusion, and an outer circumferential surface that is a perfect circle that follows the inner circumferential surface of the pinch roller. A retaining protrusion is integrally provided on the outer periphery, and each split sleeve is fitted onto the outer periphery of the bail rod and the braking protrusions on the inner surfaces of the pair of bearing ribs are pressed against the flat parts on both sides of the bail rod. Although it cannot rotate with respect to the bail rod, it is able to slide in the axial direction while receiving a braking force, and the pinch roller has its annular portion and retaining projection against the outer periphery of the pair of bearing ribs. A paper bail device for a typewriter or the like, characterized in that the paper bail device is rotatably fitted between the paper bail devices.