JP4298851B2 - Air shaft - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to Rue Ah shaft to support the core tube for winding the paper.
[0002]
[Prior art]
Conventionally, an air shaft that supports a core tube for winding paper or the like, as described in Japanese Utility Model Publication No. 63-183148, is provided by supplying air into a hollow shaft body that is rotationally driven. An inflating air tube is provided, and a plurality of lugs protruding from the outer surface of the shaft main body due to the expansion of the air tube are mounted between the shaft main body and the air tube.
[0003]
In order to wind the paper around the core tube supported by the air shaft, the air in the air tube is discharged in advance and the lug is retracted from the outer surface of the shaft body, and the paper is wound into the core tube. Insert the shaft body.
Next, air is supplied into the air tube, and the lug is pushed radially outward by the expansion of the air tube. The tip of the lug protrudes from the outer surface of the shaft body and is pressed against the inner peripheral surface of the core tube. Hold outside the shaft. Thereafter, one end of the paper is stuck to the core tube, and the shaft is rotated to drive the paper around the outer periphery of the core tube.
After the winding is completed, the air in the air tube is discharged, the lug is retracted to the inside of the shaft main body, and after removing the pressing of the lug to the core pipe, the core pipe is detached from the shaft main body, Remove the rolled paper wound around the core tube.
[0004]
However, the force to wind the paper applies a pressure to decenter the core tube with respect to the axis of the air shaft, so that the center axis of the core tube and the center axis of the shaft body are shifted, so that the paper At the maximum, the core tube and the shaft main body are swung with a width corresponding to the gap, and as a result, the paper wound around the core tube may be in a non-uniform roll shape.
In order to prevent this, the gap between the shaft body and the core tube was made as narrow as possible, but if this gap is made too narrow, it becomes difficult to insert the air shaft when there is a deformation such as bending in the core tube. There was a limit.
[0005]
[Problems to be solved by the invention]
It is an object of the present invention to provide an air shaft that prevents a shake of a sheet of paper or the like due to shaft runout between a core tube and a shaft body and that is easy to insert into the core tube.
[0006]
[Means for Solving the Problems]
The present invention relates to a hollow shaft body that is rotationally driven, an air tube that is disposed along the axial direction inside the shaft body, and that expands when supplied with air, and a diameter between the shaft body and the air tube. An air shaft that is interposed along the direction and protrudes from the outer surface of the shaft body due to expansion of the air tube, and that supports the winding core tube, and is detachably inserted into the core tube The outer diameter of the shaft body is limited to only two locations facing both ends in the axial direction, and the outer diameter of the shaft body is slightly larger than the outer diameter of the shaft body, thereby suppressing the shaft runout. The protruding ridge is formed along the circumferential direction.
[0007]
After the air tube is shrunk and the lug is immersed inside the shaft body, the air shaft is inserted into the core tube, and then the air tube is expanded so that the lug protrudes from the outer surface of the shaft body. Is brought into contact with the inner surface of the core tube to support the core tube around the air shaft.
Next, after attaching one end of a raw material such as paper to the outer surface of the core tube, the air shaft is rotated to wind the paper or the like around the outer surface of the core tube. After the winding is completed, the air in the air tube is again discharged, the air tube is contracted, the lug is immersed in the shaft body, and the core tube is pulled out together with the paper wound on the outer surface.
When winding paper or the like on the outside of the core tube, even if pressure is applied to the core tube from the outside, the ridges of the shaft main body abut on the inner periphery of the core tube to suppress the deflection of the core tube.
Since the protrusions are provided only at two locations facing both ends of the core tube, the air shaft can be easily inserted into and removed from the core tube even if the core tube is deformed such as bending.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIGS. 2 and 3, the air shaft 1 includes a hollow shaft body 2 that is rotationally driven by an appropriate drive source, and an inflatable / contractible structure that is disposed along the axial direction inside the shaft body 2. Consists of an air tube 3 and a plurality of lugs 4 interposed along the radial direction between the shaft body 2 and the air tube 3 and projecting from the outer surface of the shaft body 2 due to the expansion of the air tube 3, and paper or the like is wound around The core tube 5 to be inserted is detachably inserted.
[0009]
The shaft body 2 is formed slightly longer than the core tube 5, and an insertion hole 6 for allowing the outer end portion of the lug 4 to be inserted and retracted is formed in the peripheral wall. The insertion holes 6 are long holes that are long in the axial direction. In the example shown in the drawing, four holes are formed at regular intervals along the circumferential direction, and three holes are formed in the axial direction.
Further, as shown in FIG. 1, protrusions 7 having outer diameters slightly larger than the outer diameter of the shaft body 2 are spaced apart from each other at both axial ends of the outer peripheral surface of the shaft body 2. It is formed along the circumferential direction. The outer diameter of the protrusion 7 is slightly smaller than the inner diameter of the core tube 5, and the difference is about 0.5 mm.
[0010]
The air tube 3 is made of an elastic body such as rubber or synthetic resin, and is expanded by supplying air and contracted by discharging air.
As shown in FIG. 3, the lug 4 has a cross section that matches the insertion hole 6 of the shaft body 2, and four lugs 4 are arranged at substantially equal intervals along the circumferential direction of the shaft body 2 so as to correspond to the communication hole 6. Three are arranged in the axial direction.
Further, the lug 4 is formed in an arc shape so that the inner circumference is along the outer surface of the air tube 3 and the outer circumference is along the inner surface of the core tube 5.
[0011]
When the air tube 3 is expanded by supplying air, the lug 4 moves radially outward in the insertion hole 6 of the shaft body 2, and the outer end portion protrudes from the outer surface of the shaft body 2. When air is discharged and the air tube 3 contracts, the lug 4 moves inward in the radial direction through the insertion hole 6 and is completely immersed in the insertion hole 6.
[0012]
Next, winding of paper by the air shaft 1 will be described.
The air tube 3 is contracted in advance, and all the lugs 4 are immersed in the shaft body 2.
The air shaft 1 is inserted into the core tube 5. At this time, the gap between the ridge 7 of the shaft body 2 and the core tube 5 is as small as 0.5 mm, but the ridge 7 is formed at only two locations facing both axial ends of the core tube 5. Therefore, even if the core tube 5 is deformed such as bending, the air shaft 1 can be smoothly inserted.
[0013]
Further, when air is supplied into the air tube 3, the air tube 3 expands and its outer surface presses the inner periphery of the lug 4 outward in the radial direction.
Then, the outer end portion of the lug 4 protrudes from the outer surface of the shaft body 2, contacts the inner surface of the core tube 5, and supports the core tube 5.
Next, after sticking one end of a raw material such as paper to the outer surface of the core tube 5 and rotating the shaft body 2 with an appropriate drive source, the air tube 3, the lug 4 and the core tube 5 rotate together. The paper is wound up in a roll shape along the outer surface of the core tube 5.
At this time, the core tube 5 is pressed to the opposite side of the contact portion with the paper by the force of winding the paper, but the ridges 7 of the shaft body 2 are in contact with both axial end portions of the inner surface of the core tube 5, The deflection width of the original fabric of paper or the like accompanying the deflection of the core tube 5 can be suppressed to 0.5 mm, which is the difference between the outer diameter of the ridge 7 and the inner diameter of the core tube 5.
[0014]
When the winding of the paper is completed, the rotation of the shaft body 2 is stopped, the air in the air tube 3 is discharged, and the air tube 3 is contracted. With the contraction of the air tube 3, the lug 4 moves in the axial direction of the shaft body 2, and the outer end of the lug 4 moves backward and separates from the inner surface of the core tube 5.
Thereafter, the core tube 5 is pulled out along the axial direction of the shaft body 2 together with the rolled-up paper. Also at this time, the protrusion 7 of the shaft main body 2 provided only at two places does not obstruct the removal.
[0015]
【The invention's effect】
According to the air shaft of the present invention, when paper or the like is wound around the core tube, even if pressure is applied to decenter the core tube with respect to the shaft body, the protrusions formed on the outer peripheral surface of the shaft body are Because it is in contact with the inner surface of the core tube and suppresses large shaft wobbling of the core tube, the width of the raw material such as paper should be kept smaller than the slight difference between the inner diameter of the core tube and the outer diameter of the ridge. This makes it possible to wind paper or the like into a uniform roll.
In addition, since the protrusions are formed at both ends in the axial direction of the shaft body, the air shaft can be easily inserted into and removed from the core tube even if the core tube is bent or deformed. it can.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an essential part of an air shaft according to an embodiment of the present invention. FIG. 2 is an overall longitudinal sectional view of the same. FIG. 3 is a transverse sectional view of the same.
1 Air shaft 2 Shaft body 3 Air tube 4 Lug 5 Core tube 6 Insertion hole 7 Projection

Claims (1)

A hollow shaft body that is rotationally driven, an air tube that is disposed along the axial direction inside the shaft body, and that expands when supplied with air, and a radial direction between the shaft body and the air tube In the air shaft that is interposed and is formed of a plurality of lugs that protrude from the outer surface of the shaft body due to the expansion of the air tube, and that supports the winding core tube, the air shaft faces both axial ends of the outer peripheral surface of the shaft body. A protrusion is formed along the circumferential direction having an outer diameter slightly larger than the outer diameter of the shaft main body, spaced apart from each other only at a location, and suppressing axial runout of the core tube. Air shaft to do.

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