JPH0825675B2 - Core tube holder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cylindrical core tube made of paper,
The present invention relates to a core tube holder that is attached to both ends of the core tube and holds the core tube with lugs when winding a sheet of plastic or the like or when rewinding a sheet wound around the core tube.

[0002]

2. Description of the Related Art Conventionally, as this seed tube holder, an air chuck system in which an air cylinder is used to expand a lug outward in the radial direction, and as disclosed in Japanese Utility Model Publication 5-2515. There is a so-called mechanical chuck system.

The former includes an air cylinder and a tapered cam member axially driven by the air cylinder, an air control device, and is connected to an air supply source through an air pipe.

As for the latter, as shown in FIG.
A return mechanism 5 including a holder main body 51 fixed to a plurality of lugs 56, a plurality of lugs 56, a sleeve 57 and a coil spring 58.
3 and a cap 54 fixed to the tip of the main body 51. A plurality of guide grooves 59 are formed on the holder main body 51 at equal intervals in the circumferential direction, and the guide groove 59 has a tapered bottom surface 59a whose diameter increases as it goes to the root side of the main body. In addition to being formed, an enlarged portion 59b is formed at the bottom of the groove 59 as shown in FIG. It has a so-called "ditch groove" structure. Each rug 56
Is fitted to each of the guide grooves 59 so as to be movable in the groove length direction, and integrally provided with a guide body 60 at an inner end in the radial direction for engaging with the expanded diameter portion 59b of the guide groove 59. Therefore, it is prevented from slipping out in the radial direction. The lug 56 is formed with an outward flange 62 with which the axial end Ta of the core tube T abuts.

In the core tube holder shown in FIGS. 10 and 11, the holder is inserted into the inner surface of the core tube T, and the flange 62 of the lug 56 is brought into contact with the axial end edge Ta of the core tube T. From this state, by further pushing the holder main body 51 toward the tip side,
The lug 56 expands radially outward by the wedge action of the bottom surface 59a of the guide groove 59, and the outer peripheral gripping surface of the lug 56 causes
The inner surface of the core tube T is held in pressure contact.

Another conventional mechanical chuck method is Japanese Utility Model Laid-Open No. 4-51454, which is formed in a holder body by fitting a bottomed cylindrical casing into the holder body so as to be movable in the axial direction. On the outer peripheral surface of the taper, a dovetail groove similar to that shown in FIG. 10 is formed, and a lug is slidably arranged in the dovetail groove. It is a structure that moves along the surface and projects outward in the radial direction.

[0007]

In the former air chuck method, since an air cylinder, a tapered cam member, an air control device, an air pipe, etc. must be provided, the cost increases and the weight of the holder increases, It takes time to handle. In addition, for example, an operator needs to perform an air control operation each time the core tube is detached and attached. on the other hand,
The cost will be higher if the air control is automated.

In the latter mechanical chuck system shown in FIG. 10, the guide groove 59 that engages the lug 56 is a "deep groove", and the bottom surface 59a thereof changes in depth from the tip side of the main body to the root side. Since it has a complicated shape that
The machining of the guide groove 59 is very troublesome and the machining cost is high.

[0009] Further, another conventional example of an actual flat opening 4-51454.
Similarly to the case of FIG. 10, the holder of No. 10 also uses the dovetail groove, so that the processing cost is high and the lug is moved using the bottomed cylindrical casing. Therefore, for example, at the time of core tube mounting work, if the axis of the core tube and the axis of the holder are misaligned, the tip of the casing contacts the edge of the core tube before the lug is fitted into the inner surface of the core tube. As a result, the lug may open and the core tube may not be attached.

[0010]

[Means for Solving the Problems]

(Invention of Claim 1) Explaining with reference to the drawings and reference numerals corresponding to the attached embodiment, in FIG. 2, the core tube holder is moved from the root side fixed to the rotary shaft 11 to the tip side. A holder main body 1 having a tapered outer peripheral surface 7 having a small diameter, a plurality of lugs 6 arranged so as to surround the tapered outer peripheral surface 7 and having a tapered inner peripheral surface 17, and the lugs 6 are attached to the tip side. And a return mechanism 3 for urging.

Each lug 6 has a generally arcuate outer peripheral gripping surface 18 and an outwardly facing flange 19 that abuts against the axial end edge of the core tube. It is a core tube holder that expands the diameter of the lug 6 by moving the lug 6 in an axial direction and press-holds the inner surface of the core tube with the outer peripheral gripping surface 18.

In such a core tube holder, the holder body 1
A key 15 extending parallel to the outer peripheral surface 7 is fixed to the tapered outer peripheral surface 7, and a key groove 21 extending parallel to the inner peripheral surface 17 is formed on the tapered inner peripheral surface 17 of each lug 6. By engaging the groove 21 with the key 15, each lug 6 is movable in the key length direction with respect to the holder body 1 and fixed in the rotation direction.

A cap 4 having a cylindrical guide portion 4a for guiding the tip portion of the lug 6 from the outside in the radial direction so as not to fall off is fixed to the tip of the holder body 1.

(Invention according to Claim 2) In the core tube holder according to Claim 1, as shown in FIG.
1a is brought into contact with and supported by the radially outer end surface 15a of the key 15, and the inner peripheral surface 17 of the lug 6 is floated from the tapered outer peripheral surface 7.

(Invention of Claim 3) In the core tube holder according to claim 1, as shown in FIG. 7, the bottom surface 21a of the key groove 21 is floated from the radially outer end surface 15a of the key 15, and the lug 6 is provided. Is supported by the inner peripheral surface 17 on the tapered outer peripheral surface 7.

(Invention of Claim 4) In the core tube holder according to claim 1, the return mechanism 3 is, as shown in FIG.
The lug 6 is fitted to the holder body 1 so as to be axially movable.
The pressing ring 24 is in contact with the end surface of the lug 6 on the root side and an elastic member (for example, a coil spring 23) that presses the pressing ring 24 against the lug 6. A stopper portion (step portion 32) is formed to prevent the stopper from falling out in the radial direction.

[0017]

In the invention described in claims 1, 2 and 4, FIG.
The lug 6 in the reduced diameter state is inserted into the inner surface of the core tube T. At this time, even if the axis of the core tube T is deviated from the axis of the holder, the cap 4 only contacts the core tube T, so that the lug 6 does not expand due to a malfunction. Edge Ta of core tube T
When the holder main body 1 is moved forward after the outward flange 19 of the lug 6 comes into contact with the lug 6, the lug 6 is held in a state of being axially locked by the core tube T, and only the holder main body 1 is returned. Since it will move forward against 3, the key 1, for example
The key groove bottom surface 21a is pushed outward by the outer end surface 15a of 5 to expand the entire diameter of the lug 6. As a result, the arcuate outer peripheral gripping surface 18 of the lug 6 is pressed against the inner surface of the core tube over substantially the entire circumference to hold the core tube.

In the invention according to claim 3, when the lugs 6 move and expand in diameter, each lug 6 is supported not by the key groove bottom surface 21a but by the inner peripheral surface 7 of the lug 6. The peripheral surface 17 slides on the tapered outer peripheral surface 7.

[0019]

According to the invention of claim 1, (1) a plurality of lugs 6 are arranged around the tapered outer peripheral surface 7 of the holder main body 1, and the lugs 6 are formed by using the keys 15 and the key grooves 21. The key 4 is movable in the key length direction and fixed in the rotational direction, and the cap 4 prevents the lug 6 from falling off. Therefore, as in the conventional mechanical chuck method of FIG. Compared to the structure that forms and directly engages the lug,
The cross-sectional shape of the groove is simplified, the groove processing is less troublesome, the processing cost can be reduced, and the lug can be easily assembled.

(2) Since a plurality of arcuate lugs 6 are arranged around the tapered outer peripheral surface 7 of the holder main body 1 and the key groove 21 formed on the inner peripheral surface of the lug is engaged with the key 15.
It is possible to secure a large area of the outer peripheral gripping surface 18 of the lug 6 in the circumferential direction without complicating the shape of the lug 6.
The entire circumference of the inner surface of the core tube can be reliably gripped.

(3) Compared with the conventional air chuck method, a cylinder, piping, etc. are not required, so that weight reduction, cost reduction and easy maintenance can be achieved.

(4) Since the cap 4 fixed to the front end surface of the main body is provided with a guide portion for guiding the front end portion of the holder main body 1 from the outside in the radial direction, the lug 6 when not in operation is provided. It is possible to prevent the cap 4 from falling off, and by appropriately increasing the outer diameter of the tubular guide portion, even when the axial center of the core tube is eccentric from the holder shaft axis when inserting into the inner surface of the core tube. By hitting, it is possible to prevent an erroneous operation in which the lug moves before the core tube is attached, as compared with the conventional structure of Japanese Utility Model Laid-Open No. 4-51545.

According to the second aspect of the invention, (1) the lug 6 has a structure for slidably supporting the lug 6.
Since the bottom surface 21a of the key groove is abutted against and supported by the outer end surface 15a of the key 15, and the lug 6 moves on the end surface 15a, the area of the outer peripheral gripping surface 18 of the lug 6 is increased. Even if it is taken, the sliding friction surface at the time of the diameter expansion operation of the lug 6 is reduced, the pressing force in the axial direction can be reduced, and the diameter expansion operation becomes light.

(2) Since each lug 6 is supported via the key groove bottom surface 21a, even if the posture of the outer peripheral surface gripping surface 18 does not slightly match the shape of the inner surface of the core tube when the lug diameter is expanded, the key 15 and the key The rattling between the groove 21 and the groove 21 allows the posture to be self-controlled to some extent and can be matched with the inner surface of the core tube.

According to the third aspect of the present invention, the lug 6 is fixed in the rotational direction by the key 15, and the lug inner peripheral surface 17 and the taper outer peripheral surface 7 are brought into contact with each other to support the lug 6 in the axial direction and the radial direction. Since it is performed, the support of the lug 6 during the diameter expanding operation is stable.

According to the invention of claim 4, as the return mechanism 3, since the elastic member is arranged together with the pressing ring 23 on the outer peripheral side of the holder main body 1, as compared with the spring built-in type. And the group meeting is easy. Also,
Since the stopper portion (step portion 32) of the pressing ring 23 prevents the root side portion of the lug 6 from falling off, it is possible to reliably prevent the lug from falling off when the core tube is not attached, even though the structure is a key.

[0027]

[First Embodiment] FIGS. 1 to 4 show a core tube holder to which the inventions according to claims 1, 2 and 4 of the present application are applied, and in FIG. The holder includes a holder main body 1, a plurality of lugs 6 for pressing and holding the inner surface of the core tube T, a return mechanism 3 for urging the lugs 6 toward the tip end side in the axial direction of the main body 1, and a main body. It is composed of a cap 4 and the like at the tip. As the material of the core tube T, cardboard, plastic or the like is used.

The holder body 1 has a root side on the side fixed to the rotary shaft 11 of the machine (right side in FIG. 2) and a tip side on the side inserted into the core tube T (left side in FIG. 2). An outward flange 8 and a brazing recess 9 are formed at the root end. The recess 9 for anchoring is fitted in the protrusion 12 for anchoring of the rotating shaft 11, whereby the centering is performed. The flange 8 is fixed to the end surface of the rotating shaft 11 with a bolt or the like. The rotary shaft 11 is connected to an appropriate rotary drive source so that the driving force can be intermittently connected, and is configured to advance and retract in the axial direction by an appropriate forward / backward operation mechanism.

A tapered outer peripheral surface 7 is formed at a portion closer to the tip end than the axially substantially middle portion of the holder main body 1 as the diameter becomes smaller toward the tip end. Taper outer peripheral surface 7
Has a key hole 13 formed in parallel with the outer peripheral surface 7, and a key 15 is press-fitted and fixed in the key hole 13 so as not to move in the rotational direction and the axial direction.

The key 15 has an inner end surface 15b in the radial direction and an outer end surface 15a formed in parallel with each other, whereby the outer end surface 15a of the key 15 has an outer peripheral tapered surface 7 with respect to the rotation axis. Inclined at the same angle as the taper angle θ of
The posture is parallel to the tapered outer peripheral surface 7.

A taper outer peripheral surface 7 is provided on the inner peripheral surface of each lug 6.
Inner surface 17 of the taper with the same taper angle θ
The taper guide surface 20, the outer peripheral gripping surface 18 for holding the core tube, and the outward flange 19 are integrally formed on the outer side in this order from the tip end side. A key groove 21 is formed on the tapered inner peripheral surface 17 so as to extend over the entire length of the inner peripheral surface 17 in the axial direction. The outer peripheral gripping surface 18 includes
A large number of slip-resistant narrow grooves extending in the axial direction are formed.

In FIG. 4 showing the IV-IV cross section of FIG. 2, each lug 6 is formed in a shape obtained by dividing an annular body into four equal parts in the circumferential direction. That is, the cross section is divided into four lugs 6 each having a quarter-arc shape, and the four lugs 6 are annularly arranged so as to surround the tapered outer peripheral surface 7. Rug 6
The arcuate curvature of the outer peripheral gripping surface 18 of is preferably matched to the inner surface of the core tube T, but in the drawings of this embodiment, it is described as slightly smaller than the inner surface of the core tube T. The gripping surfaces 18 of the four lugs 6 are arranged along the same circumference.

One key groove 21 is formed for each lug 6, is located at the center of the circumferential width of each lug 6, and has a simple rectangular cross section. . The relationship between the depth d1 of the key groove 21 and the protrusion height h1 of the key 15 from the tapered outer peripheral surface 7 is as follows.
1 is set to be slightly larger (for example, about 1 to 3 mm) than the groove depth d1. As a result, when the lug is assembled, the key groove bottom surface 21a is located at the outer end surface 15 of the key 15.
The inner peripheral surface 17 of the lug 6 is slidably brought into contact with and supported by a.
It floats with a constant clearance C1 from the tapered outer peripheral surface 7.

The return mechanism 3 shown in FIG. 2 comprises a coil spring 23 and a pressing ring 24. A cylindrical ring guide 27 having the same diameter as the large-diameter end of the tapered outer peripheral surface 7 is formed in a portion of the holder main body 1 closer to the root than the tapered outer peripheral surface 7, and the pressing ring 2 is formed on the ring guide 27.
4 is fitted so as to be movable in the axial direction, and is in contact with the root side edge of the lug 6.

The coil spring 23 is contracted between the pressing ring 24 and the main body flange 8 and biases the lug 6 toward the tip end side with a constant elastic force via the pressing ring 24. A stopper step portion 29 is formed on the ring guide 27, whereby a relative maximum stroke amount S1 in the axial direction between the lug 6 and the holder main body 1 is set.

On the surfaces of the main body flange 8 and the pressing ring 24 which face each other, annular recesses 30 and 3 for spring guide are respectively provided.
1 is formed, and both ends of the coil spring 23 are fitted in the recesses 30 and 31, respectively. Further, an inwardly facing annular step portion 32 is formed on the tip end side of the pressing ring 24 so as to prevent the end portion on the root side of the lug 6 from falling off in the radial direction.

The cap 4 is formed in a disk shape and integrally has a cylindrical guide portion 4a at the outer peripheral end thereof, and is fixed to the tip end surface of the holder main body 1 by a plurality of bolts 37. The guide portion 4a extends toward the root side, and its outer diameter is such that the lug 6 does not project outward in the radial direction when the diameter is reduced. A taper guide surface 36 corresponding to the tip taper guide surface 20 of the holder body 1 is formed inside the guide portion 4a.
0 and 36 are the same angle as the taper angle θ of the tapered outer peripheral surface 7, and the tip edge of the lug 6 abuts the cap 4.
When the diameter is reduced, a slight gap is set between the guide surfaces 20 and 36. The axial length S2 of the tapered guide surface 36 is longer than the axial maximum stroke S1.

The core tube holders as shown in FIG. 2 are arranged in a pair so as to be opposed to each other on the same axis at intervals in the axial direction. To support.

The operation of the embodiment will be described. The holders in a reduced diameter state as shown in FIG. 2 are fitted inside the both ends of the core tube T, and the holder body 1 is advanced to the distal end side in the axial direction, and the outward flange 19 is brought into contact with the core tube end surface Ta. Let At the time of this fitting work, even if the axis of the core tube T is slightly deviated from the axis of the holder main body 1, the tip tapered guide surface 35 of the cap 4 comes into contact with the end surface Ta of the core tube to align the cores. The lug 6 is automatically fitted to the outer periphery of the lug 6. Of course, at that time, the lug 6 does not expand just by hitting the core tube T with the cap 4, and the conventional practical application No. 4-51454 is used.
It is possible to prevent malfunctions such as issues.

When the holder main body 1 is further advanced after the outward flange 19 contacts the core tube end Ta, the lug 6 is kept stopped by the core tube end Ta and only the holder main body 1 has a coil spring. It moves forward against the elastic force of 23. During this forward movement, each lug 6 is moved radially outward by the key groove bottom surface 21a being pushed outward by the outer end surface 15a of the key 15, so that each lug 6 moves radially outward. The diameter is increased as a whole, and the outer peripheral gripping surfaces 18 each having a ¼ arc shape are pressed against the inner surface of the core tube to hold them.

Since the inner surface of the core tube is pressed and supported by the four holding surfaces 18 of the 1/4 circular arc shape, the pressing area is wide, the core shape of the core tube itself is not broken, and the core is held with a reliable gripping force. Hold the tube T.

[0042]

[Second Embodiment] FIGS. 5 to 9 show a core tube holder to which the invention according to claim 3 of the present application is applied. Parts having the same names as those of the first embodiment are designated by the same reference numerals. The description of the parts having the same structure is omitted, and only different contents will be described.

In FIG. 7, the depth d2 of the key groove 21 formed on the tapered inner peripheral surface 17 of each lug 6 is smaller than the outward protruding height h2 of the key 15 (for example, about 1 to 3 mm).
The clearance C2 is set between the key groove bottom surface 21a and the outer end surface 15a of the key 15 when the lug is assembled, while the inner peripheral surface 17 of the lug 6 becomes the tapered outer peripheral surface 17. It comes into contact with and is supported. That is, the key 15 has a function of fixing the lug 6 in the rotation direction,
It functions as an axial guide on both sides of the groove, but the lug 6
The function of supporting the radial direction is not fulfilled.

In this embodiment, the diameter of the tapered inner peripheral surface 17 of the lug 6 is set so as to match the tapered outer peripheral surface 7 in the reduced diameter state of FIG. Therefore, when the lug 6 expands radially outward, as shown in FIGS. 8 and 9, both ends 1 in the circumferential direction of the inner peripheral surface 17 of each lug 6 are formed.
7a is in sliding contact with the tapered outer peripheral surface 7. That is, each lug 6 is supported at two points by the both circumferential end portions 17 a of the inner peripheral surface 17.

The basic operation of this embodiment is the same as that of the first embodiment, but when the lugs 6 are expanded in diameter, each lug 6 is supported at two points by the inner peripheral end portions 17a. Therefore, a force that pushes the lugs 6 in the axial direction needs to be slightly larger than that in the first embodiment. However, since the lugs 6 are supported at two points, the postures of the lugs 6 are stable regardless of the amount of axial movement. To do.

[0046]

[Other Examples]

(1) Each lug 6 is provided with its inner peripheral surface 17 as in the second embodiment.
In the structure of supporting on the taper outer peripheral surface 7 with
The diameter of the inner peripheral surface 17 can be set so as to match the taper outer peripheral surface 7 when the diameter is expanded to the state of gripping the core tube as shown in FIG. With such a structure, the inner peripheral surface 17 of the lug fits closely with the outer peripheral surface 7 of the taper when the core tube is gripped, and the holding of the core tube is further stabilized.

(2) In the first and second embodiments, the holder main body 1 has the outwardly facing flange 8 at the root side end, but the shaft type specification without the flange is adopted. It is also possible to do so. In this case, for example, the rotary shaft 11 is inserted into a shaft mounting hole as shown in FIG. 2 and fixed with a key or the like.

(3) The lug 6 may have an equal division structure of three equal divisions or five or more equal divisions.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of a core tube holder to which the invention described in claims 1, 2 and 4 of the present application is applied.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1 showing a state when the diameter is reduced.

FIG. 3 is a cross-sectional view taken along the line II-II in FIG. 1 showing a state at the time of expanding the diameter.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a partially longitudinal side view of a core tube holder to which the invention according to claim 3 of the present application is applied, showing a state when the diameter is reduced.

FIG. 6 is a partially longitudinal side view of the same core tube holder as in FIG. 5, showing a state when the diameter is expanded.

7 is a sectional view taken along line VII-VII of FIG.

FIG. 8 is a sectional view taken along line VIII-VIII of FIG.

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a partially longitudinal side view of a conventional example.

11 is a sectional view taken along line XI-XI of FIG.

[Explanation of symbols]

 1 retainer body 3 return mechanism 4 cap 6 lug 7 taper outer peripheral surface 18 outer peripheral gripping surface 19 outward flange 21 key groove 21a groove bottom 23 coil spring 24 pressing ring 36 guide surface

Claims (4)

[Claims] 1. A holder main body having a tapered outer peripheral surface that is fixed to a rotary shaft and has a diameter that decreases from a root side toward a tip side, and a retainer main body that is arranged so as to surround the tapered outer peripheral surface and has a tapered inner peripheral surface. A plurality of lugs and a return mechanism for urging the lugs toward the tip end side are provided, and each lug has a generally arcuate outer peripheral gripping surface and an outward flange that contacts an axial end edge of the core tube. , A core tube holder in which the inner diameter of the lug is expanded by moving the holder body relative to the lug relative to the lug, and the inner surface of the core tube is held in pressure contact with the outer peripheral gripping surface of the holder body. , A key extending parallel to the outer peripheral surface is fixed, and on the taper inner peripheral surface of each lug,
By forming a key groove extending parallel to the inner peripheral surface and engaging the key groove with the key, each lug is movable in the key length direction with respect to the holder main body and fixed in the rotation direction, and held. A core tube holder characterized in that a cap having a guide portion for guiding the tip portion of the lug from the outside in the radial direction is fixed to the tip of the tool body. 2. The core tube holder according to claim 1, wherein a bottom surface of the key groove is brought into contact with and supported by a radially outer end surface of the key,
A core tube holder characterized in that the inner peripheral surface of the lug is floated from the tapered outer peripheral surface. 3. The core tube holder according to claim 1, wherein the bottom surface of the key groove is floated from the outer end surface in the radial direction of the key, and the lug is supported by the inner peripheral surface thereof on the tapered outer peripheral surface. Core tube holder. 4. The core tube holder according to claim 1, wherein the return mechanism includes a pressing ring fitted to the holder body so as to be movable in the axial direction and abutting against the root-side end surface of the lug, and the pressing ring. It consists of an elastic member that presses against the lug,
The core tube holder characterized in that the pressing ring is formed with a stopper portion for preventing the end portion of the lug on the root side from falling off in the radial direction.