GB2403708A

GB2403708A - An expandible reel, spindle or the like.

Info

Publication number: GB2403708A
Application number: GB0316014A
Authority: GB
Inventors: Hsi-Tsai Chen
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-07-09
Filing date: 2003-07-09
Publication date: 2005-01-12
Anticipated expiration: 2023-07-09
Also published as: GB0316014D0; GB2403708B

Abstract

An expandible reel, spindle or the like for holding a roll of web material comprises a cylindrical shaft 3 provided with at least three elongate grooves 31 each containing an expandible bladder, each bladder having first roll contact sections 412A which prevent the roll from rotating about the shaft when the bladder is inflated and second roll contact sections 412B which ensure that the roll is held concentrically with respect to the rotational axis of the shaft. The elongate grooves retaining the inflatable bladders are substantially T-shaped having a narrower access opening 311 and a wider retaining section 312. The total area of the first roll contact sections may be less than that of the second roll contact sections. The groves may extend parallel to the longitudinal axis of the shaft or helically along its length (figure 4, not shown). The bladders may be connected to an air pumping unit. In use, the device is able to hold a web of material upon the shaft whilst reducing rotational eccentricity casued by uneven loading.

Description

1 2403708

AIRSHAFT

The invention relates to an airshaft, more particularly to an airshaft that is capable of holding a roll of web material.

An airshaft is mounted rotatably on a machine, and is expandable by use of pressurized air so as to hold a roll of web material, such as paper, rubber, plastic, metal, fabric, wire, or the like, thereon.

A conventional airshaft generally includes a shaft body and an inflatable unit retained on the shaft body.

The inflatable unit includes a plurality of inflatable bladder members that, when inflated, protrude from the surface of the shaft body to abut against a roll of web material sleeved on the airshaft so as to hold the roll on the shaft body. The roll generally includes a cardboard tubular core or a metal tubular core. In use, an inner diameter of the roll is larger than an outer diameter of the shaft body. Accordingly, when the inflatableunitisinflated,theinflatableunitexpands in radial outward directions to be able to hold the roll on the shaft body.

It is noted that the greater the extent of expansion of the inflatable unit, the larger will be the holding force exerted on the roll to ensure rotation of the roll with the shaft body. However, when the extent of expansion of the inflatable unit is unduly large, the degree of rotational concentricity of the roll with respect to the shaft body will be adversely affected in view of deformation of the roll at contact areas with the inflatable unit such that, when the shaft body rotates about an axis thereof, rotational deviation of the web material being wound on the roll is likely to occur. This problem is aggravated under high-speed conditions and during heavy web material applications.

The aforesaid rotational deviation not only affects production quality, but also subjects the shaft body to imbalanced forces that can interrupt production and that can shorten the service life of the airshaft.

Therefore, the object of the present invention is to provide an airshaft that can overcome the aforesaid

drawbacks associated with the prior art.

IS Accordingly, anairshaft of this invention comprises: an elongate shaft body having a shaft axis and an outer cylindrical shaft surface formed with at least three longitudinally extending bladder retaining grooves, each of the bladder retaining grooves being generally inverted T-shaped and having a narrower access opening formed in the shaft surface and a wider retaining section disposed between the access opening and the shaft axis; a set of elongate inflatable bladder members, each of which is received in the retaining section of a respective one of the retaining grooves; and a plurality of roll contact pieces, each of which has a biased side disposed in the retaining section of one of the retaining groovesandincontactwiththeinflatablebladdermember in the corresponding retaining groove, and a roll contacting side extending out of the corresponding retaining groove through the access opening of the corresponding retaining groove, the roll contacting side having a distal contact face.

The roll contact pieces include a set of first roll contact pieces and a set of second roll contact pieces.

The distal contact face of the roll contacting side of eachof the first rollcontact pieces forms a first height with theinflatable bladder memberin the corresponding retaining groove. The distal contact face of the roll contacting side of each of the second rollcontact pieces forms a second height with theinflatable bladder member inthecorrespondingretaininggroove.Thesecondheight is shorter than the first height.

When a roll of web material is sleeved on the shaft body, and when the inflatable bladder members are inflated, thedistalcontactfacesoftherollcontacting sides of the first roll contact pieces contact the roll of web material for holding the roll of web material on the shaft body, and the distal contact faces of the roll contacting sides of the second roll contact pieces contact the roll of web material for positioning stably the roll of web material on the shaft body.

Other features and advantages of the present inventionwillbecomeapparentinthefollowingdetailed description of the preferred embodiments with reference to the accompanying drawings, of which: Figure 1 is an assembled sectional view of the first preferred embodiment of an airshaft according to the present invention; Figure2isanassembledfragmentaryperspectiveview of the first preferred embodiment; Figure 3 is a fragmentary assembled sectional view of the first preferred embodiment; and lO Figure 4 is an assembled perspective view of the second preferred embodiment of an airshaft according to the present invention.

As shown in Figures 1 to 3, the first preferred embodiment of an airshaft according to this invention is shown to include a shaft body 3, an inflatable unit 4 retained on the shaft body 3, and an air pumping unit connected to the inflatable unit 4.

The shaft body 3 has a shaft axis (A), and an outer cylindrical shaft surface30 formed with at least three longitudinally extending bladder retaining grooves31.

Each of the bladder retaining grooves 31 is generally inverted T-shaped, and has a narrower access opening 311 formedin the shaft surface30 and a wider retaining section312 disposed between the access opening311 and the shaft axis (A). In this embodiment, each of the bladder retaining grooves 31 extends parallel to the shaft axis (A).

The inflatable unit 4 includes a set of elongate inflatable bladder members 411 and a plurality of roll contact pieces 412. Each inflatable bladder member 411 is received in the retaining section 312 of a respective one of the bladder retaining grooves 31. Each roll contact piece 412 has a biased side 4122 disposed in the retaining section 312 of one of the retaining grooves 31 and in contact with the inflatable bladder member 411 in the corresponding retaining groove 31, and a roll contacting side 4121 extending out of the corresponding retaining groove 31 through the access opening 311 of the corresponding retaining groove 31. The roll contacting side 4121 has a distal contact face 4120 distal from the inflatable bladder member 411 in the corresponding retaining groove 31.

The roll contact pieces 412 include a set of first roll contact pieces 412A and a set of second roll contact pieces 412B. The distal contact face 4120 of the roll contacting side 4121 of each of the first roll contact pieces 412A forms a first height with the inflatable bladder member 411 in the corresponding retaining groove 31. The distal contact face 4120 of the roll contacting side 4121 of each of the second roll contact pieces 412B forms a second height with the inflatable bladder member 411 in the corresponding retaining groove 31. The second height is shorter than the first height.

In this embodiment, the roll contact pieces 412 are disposed side-by-side on the inflatable bladder member 411 in the corresponding retaininggroove3l.Moreover, a total area of the distal contact faces 4120 of the roll contacting sides 4121 of the first roll contact pieces 412A is fess then that of the distalcontact feces 4120 of the roll contacting sides 4121 of the second roll contact pieces 412B.

The air pumping unit5is connected Lotheinflatable bladder members 411 and is operable so as to inflate the inflatable bladder members 411.

In use, when a roll 6 of web material is sleeved on theshaftbody3, andwhentheinflatablebladdermembers 411 are inflated with the use of the air pumping unit 5, the inflatable bladder members 411 expand in radial outward directions such that the distal contact faces 4120 of the roll contacting sides 4121 of the first roll contact pieces 412A contact the roll 6 of web material to exert a stronger force sufficient for holding the roll 6 of web material on the shaft body 3, thereby preventing removal of the roll 6 from the shaft body 3, whereas the distal contact faces 4120 of the roll contacting sides 4121 of the second roll contact pieces 412B contact the roll 6 Ofweh materiel to exert a weaker force sufficient for positioning stably the roll 6 of web material on the shaft body 3, thereby maintaining rotational concentricity of the roll 6 with respect to the shaft axis (A).

Therefore, in practice, thelengthof the first roll contactpieces4l2Adoesnothavetobetoolongtoachieve theintended effect of holding the roll6OfweLmaterial on the shaft body 3. Moreover, the second height of the second roll contact pieces 412B is only required to be large enough topositionstablytheroll6Ofwebmaterial 6 such that the second roll contact pieces 412B do not press tightly against the roll6Of web materialto avoid the undesired rotational deviation commonly

encountered in the prior art. As such, because two

complementary holding and positioning effects are respectively attributed to the first and second roll contact pieces 412A, 412B, the roll 6 of web material will not encounter the problem of rotational deviation during use of the airshaft of this invention so that a smooth rolling operation is ensured and so that the service life of the airshaft can be prolonged.

Figure4illustratesthesecondpreferredembodiment of an airshaft according to this invention. Unlike the first preferred embodiment, each of the bladder retaining grooves 31 in the embodiment of Figure 4 extends along a twisted line with respect to the shaft axis (A). The resulting helical arrangement of the roll contact pieces 412 on the shaft body 3 enhances the rotational concentricity of the roll of web material during rotation of the shaft body 3.

Claims

CLAIMS: 1. An airshaft for holding a roll of web material, comprising: an

elongate shaft body having a shaft axis and an outer cylindrical shaft surface formed with at least three longitudinally extending bladder retaining grooves, each of said bladder retaining grooves being generally inverted T-shaped and having a narrower access opening formed in said shaft surface and a wider retaining section disposed between said access opening and said shaft axis; a set of elongate inflatable bladder members, each of which is received in said retaining section of a respective one of said retaining grooves; and a plurality of roll contact pieces, each of which has a biased side disposed in said retaining section of one of said retaining grooves and in contact with said inflatable bladder member in said one of said retaining grooves, and a roll contacting side extending out of said one of said retaining grooves through said access opening of said one of said retaining grooves, said roll contacting side having a distal contact face; wherein said roll contact pieces include a set of first roll contact pieces and a set of second roll contact pieces, said distal contact face of said roll contacting side of each of said first roll contact pieces forming a first height with said inflatable bladder member in said one of said retaining grooves, said distal contact face of said roll contacting side of each of said second roll contact pieces forming a second height with said inflatable bladder memberin said one of said retaining grooves,saidsecondheightbeingshorterthansaidfirst height; whereby, when the roll of web material is sleeved on said shaft body, and when said inflatable bladder members are inflated, said distal contact faces of said roll contacting sides of said first roll contact pieces contact the roll of web material for holding the roll of web material on said shaft body, and said distal contact faces of said roll contacting sides of said second roll contact pieces contact the roll of web materialforpositioning stately the rollof web materiel on said shaft body.
2. The airshaft as claimed in Claim 1, wherein a total area of said distalcontact feces of said rollcontacting sides of said first roll contact pieces is less than that of said distalcontact feces ofeaidrollcontacting sides of said second roll contact pieces.
3. The airshaft as claimed in Claim 1, wherein each of said bladder retaining grooves extends parallel to the shaft axis.
4. The airshaft as claimed in Claim 1, wherein each of said bladder retaining grooves extends along a twisted line with respect to the shaft axis. 1 0
5.TheairshaftasclaimedinClaiml,furthercomprising anairpumping unit connected Losaidinflatable bladder members and operable so as to inflate said inflatable bladder members.
6. The airshaft as claimedinClaiml, wherein said roll contact pieces are disposed side-by-side on said inflatable bladder memberin said one of said retaining grooves.
7. A spindle substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

, , ,

7.Theairshaft substantially ashereinbefore described with reference to end asillustratedinthe accompanying drawings.

Amendments to the claims have been filed as follows 1. A spindle for holding a roll of web material comprising: an elongate shaft body having a shaft axis and an outer cylindrical shaft surface formed with at least three longitudinally extending bladder retaining grooves, each of the bladder retaining grooves being generally inverted T- shaped and having a narrower access opening formed in the shaft surface and a wider retaining section disposed between the access opening and the shaft axis; a set of elongate inflatable bladder members, each of which is received in the retaining section of a respective one of the bladder retaining grooves) a set of first roll contact pieces, each of which is received in one of the bladder retaining grooves and has a biased side disposed in the retaining section of the bladder retaining groove and in contact with an inflatable bladder member, and a roll contacting side extending out of the bladder retaining groove through the access and having a distal contact surface forming a first height with the inflatable bladder member; and a set of second roll contact pieces, each of which is received in a respective one of the bladder retaining grooves and has a biased side disposed in the retaining section of the bladder retaining groove and in contact with an inflatable bladder member, and a roll contacting side extending out of the bladder retaining groove through the access opening and having a distal contact surface forming a second height, that is shorter than the first height, with the inflatable bladder member; such that when the roll of web material is sleeved on the shaft body, and the inflatable bladder members are < 1= inflated, the distal contact faces of the first roll contacting pieces contact the roll of web material to hold it on the shaft body and the distal contact faces of the second roll contact pieces contact the roll of web material to position it concentrically with respect to the shaft axis.

2. A spindle according to claim 1, wherein a total area of the distal contact faces of the first roll contact pieces is less than that of the distal contact faces of the second roll contact pieces.

3. A spindle according to claim 1 or claim 2, wherein each of the bladder retaining grooves extends parallel to the shaft axis.

4. A spindle according to claim 1 or claim 2, wherein each of the bladder retaining grooves extends along a helical path with respect to the shaft axis.

5. A spindle according to any preceding claim, further comprising an air pumping unit connected to the inflatable bladder members and operable so as to inflate the inflatable bladder members.

6. A spindle according to any preceding claim, wherein the first roll contact pieces and the second roll contact pieces are disposed side-byside in each of the bladder retaining grooves. t3