GB2137590A

GB2137590A - Reel support

Info

Publication number: GB2137590A
Application number: GB08309480A
Authority: GB
Inventors: Peter Barton
Original assignee: Linotype Paul Ltd
Current assignee: Linotype Paul Ltd
Priority date: 1983-04-07
Filing date: 1983-04-07
Publication date: 1984-10-10

Abstract

A web reel is supported by axially spaced hubs (3) each of which has an elastic 'O' ring (13) which fills the space between the hub and core (2) and is displaced from a position of rest in groove (11) when the hub enters the core (2) such that the 'O' ring is compressed and exerts a pressure resiliently urging the hub (3) against withdrawal from the core. One hub may be secured by pin (16) to a shaft (17) which passes through the core interior while the other hub can be slid axially along the shaft to accommodate different widths of reel. Each hub either has a second groove (10) spaced from the first groove (11) by land (12) of smaller diameter than portions (7 and 8), the O-ring being displaced from groove (11) to groove (10), or else the hub has a truncated conical portion over which the O-ring rolls as the hub is inserted into the core. An end disc (5) may be carried by each hub to act as an edge guide for web being dispensed from the reel (eg light sensitive film being fed from the reel to a photocomposing machine). Each hub may also carry a boss (6) to which may be imparted driving or braking control. <IMAGE>

Description

SPECIFICATION Reel supports The present invention relates to reel supports, particularly to reel supports aligning and locating reels of material, for example reels of paper, plastic or film or the like in web form, which are wound onto or from a hollow core for location in a stand or support and associated with means for winding or unwinding the web.

An object of the present invention is to hold a reel concentrically to its supporting hubs, carried by a shaft which itself can be accurately located in a reel support mechanism. The reel support of the present invention also allows accurate location of the reel relatively to its supporting shaft and can provide a drive coupling to the reel. Unless the reel is very accurately aligned and located uneven feeding of the web or wandering of the web can occur.

Brief description of the invention A web reel is carried on opposed hubs, one of which can be accurately located and secured to a shaft which can itself be accurately located in and secured, or be detachable from, the reel support winding or unwinding mechanism. The other hub can be slid axially along the shaft to accommodate different widths of reel within the overall width of the shaft.

Each hub is provided with two circumferentialiy extending grooves axially spaced and separated by a land which has a diameter greater than the grooves but less than that of the hub body, or with a conical surface in place of the second groove. An '0' ring of elastic material is located in one of the grooves and is translated to the other groove or onto the conical surface as the core of the reel is pressed onto the hub or the hub is pressed into the core ofthe reel, thereby aligning the reel concentrically to the shaft which carries the hubs and providing drive to the reel should it be desired positively to drive or brake the reel.

The invention is particularly applicable to reels of light sensitive film such as used in photocomposing machines, in which it is essential that the film be very evenly fed into the machine.

Example of reel support according to the invention Figure 1 is a cross section of a reel support according to the present invention.

Figure 2 is a graphical respresentation of the forces involved in pushing a hub into the core of a reel, and Figure 3 is a cross section of an alternative reel support according to the present invention.

A web material 1, for example paper, plastic, film or the like is wound onto a hollow core 2. The core may be made, for example, from cardboard or plastic.

Two hubs generally designated 3, are provided for supporting a reel; conveniently these hubs are identical and interchangeable, hence a description of one hub can be considered a description of both, with the exception that one hub is secured to a shaft as hereinafter described.

Each hub comprises a body member, generally designated 4 to which is secured an end disc 5, made from a suitable plastic or metal. The end disc 5 can act as an edge guide to a web fed from or to a reel.

A bore 15 extends through the hub 4.

A boss 6 may be integral with the body 4 or if not integral with the body may be secured to the disc 5.

One hub, the left hand hub in Figure 1, is pinned by pin 16 to a shaft 17 which passes through the bore 15 of the hub.

The shaft 17 may be removeable from the reel wind/unwind mechanism, but conveniently it is secured to the reel wind/unwind mechanism, not shown, by any suitable means which can impart rotary motion to the shaft. Thus the shaft 17 may be mounted in cantilever fashion, for example, a photocomposing machine, with one hub pinned to it, ready to receive a reel of light sensitive film.

If desired, the boss 6 may be cylindrical, as when the reel is to be free to rotate on its supporting shaft 17 or the boss may be square or provided with a cog wheel or the like on one or both hub bosses where some brake control or drive is required for the reel when the reel support is fitted into the machine.

The hub 4 includes two cylindrical portions, a long portion 7 and a short portion 8. A chamfered nose 9 is provided on the cylindrical portion 7, to assist entry of the nose 9 into the core 2 of the reel 1 during loading of the reel.

The cylindrical portions 7, 8 are separated by two circumferential grooves 10,11 axially separated bya land 12. Land 12 is of smaller diameter than the portions 7 or 8 but of greater diameter than the circumferential grooves 10, 11, which grooves are of the same diameter.

The hubs 4 are a clearance fit in the bore of the core 2 of the reel 1.

A distortable elastic '0' ring 13 rests in the circumferential groove 11 when the hub is not fitted in the core, as shown in the right hand side of Figure 1. The '0' ring may be made from rubber, a synthetic rubber, or a polyurethane having the properties of natural rubber.

In the following description it will be assumed that a reel of light sensitive film is to be fitted into a photocomposing machine.

The shaft 17 is cantilever mounted in a light tight compartment, not shown, in the composing machine, which compartment is opened when it is desired to load the machine.

Although the description is of a full reel being supplied for feeding a web of light sensitive film into the machine the invention is equally applicable to a wind on mechanism receiving a light exposed web of film to be wound onto a central core.

The left hand hub is pinned to the shaft 17 and the end disc 5 accurately locates the left hand edge of the web when the reel is located on the hub.

In referring to "left" and "right" hand hubs, it is to be understood that these hands are in relation to the hubs shown in Figures 1 and 3.

A reel is fed into the light tight compartment, opened to receive the reel, so that the core 2 can be fed over the shaft 17 and eased axially along it until the nose 9 enters the core. The hub will allow for small internal diameter variations in the reel core, of the order of + .2mm.

The core 2 is pushed along the hub until it abuts against the ring 13 whence it pushes, or rolls, it out ofthe groove, across the land 12 and into the second groove 10. At this point the core is fully home against the end disc 5 and the '0' ring 13 is resiliently urging the reel against the end disc and at the same time providing frictional drive between the core and the shaft, or as a brake to control film being wound onto ot off the reel.

The interaction of forces between the '0' ring, hub and core is diagrammatically shown in Figure 2 in which force is plotted against distance.

As the core is pushed onto the hub, it dislodges the '0' ring at a, causing a steep rise in applied force to roll it out of the groove 11, to a peak, b, when the force applied drops to c and is even to d. Between c and d the '0' ring is under pressure and distorted due to the compression of the external diameter and expansion of the internal diameter.

Continued axial movement of the core or hub rolls the '0' ring off the land 12 and the pressure drops to a negative condition e, as the '0' ring enters the groove 10, loading the core onto the hub.

At this point there is maximum loading of the hub into the core, so that the reel is resiliently urged against the end disc 5.

The reel is thus located and secured at one end, that is, at the left hand end of the reel.

The right hand hub is then pushed onto the shaft 17 and the nose 9 enters the bore of the core 2 of the reel.

Within the overall axial length of the shaft 17 the width of reel is automatically compensated by the free movement of the right hand hub along the shaft 17 until the hub is located in the reel core, ensuring that the web from the reel is edge registered from the left hand side of the reel and any width of web catered for.

Locking of the right hand hub is effected in exactly the same way as that described in respect of the left hand hub.

Removal of the expired reel is effected by pulling the right hand hub out of the core and removing the core from the shaft 17, leaving the shaft 17 ready to receive a new reel.

In the modification shown in Figure 3 the second groove 10 of Figure 1 is replaced by a truncated conical portion 100. All other parts are identical with those already described with reference to Figure 1 and the same reference numerals are applied.

After the nose 9 of a hub enters the core, the core dislodges the '0' ring 13 from its seating in the groove 11 and continued axial movement rolls the ring axially along the conical portion 100. The 'O' ring is initially deformed and is attempting to expand, the reaction being to pull the hub into the core, accurately locating the core on the hub.

The angle of slope of the conical portion is such that the '0' ring is still under compression between the conical surface and the bore of the core when the hub is fully inserted in the core.

Alternatively to the foregoing description, the shaft 17, may be readily removable from the machine receiving the reel, and both hubs are then free to move axially of the shaft, in which instance the shaft is pushed through the core of a reel and the hubs slidden along the shaft, one from each end, to locate and lock the reel onto the shaft, the completed assembly then being inserted into the machine to be fed with web from the reel.

Claims

1. A reel support including two hubs adapted to be axially slidden along a shaft two engage the opposite end of the core of a reel, each hub having an elastic '0' ring thereon which fills the space between the surface of the hub and the inside of the bore of the core of the reel, which ring is axially displaced when the hub enters the core and is placed under pressure such that the resultant force urges the hub resiliently into the core.

2. A reel support including two hubs each having two circumferential axially separated grooves, separated by a land, and an '0' ring of elastic material located in one of the grooves, which ring is displaced axially towards the other groove as the hub enters the core of the reel, placing the '0' ring under compression so that the resultant force urges the hub resiliently into the core.

3. A reel support according to Claim 2 wherein the land is of greater diameter than the grooves and of smaller diameter than the main body of the hubs.

4. A reel support including two hubs each having a truncated conical portion, and an elastic'0' ring located at one end of the truncated conical portion when the hub is outside the reel core, insertion of a hub into the core rolling the '0' ring along the truncated conical portion to displace axially the '0' ring and place it under pressure such that the resultant force urges the hub resiliently into the core.

5. A reel support according to Claim 4 wherein the '0' ring prior to insertion of a hub into the reel core, is located in a circumferential groove at one end of the truncated conical portion.

6. A reel support according to Claim 1 or 2 or 4 wherein each hub is provided with a central bore to receive an axial shaft to locate the hubs, and a reel they support, in a machine to wind or unwind a web from the reel.

7. A reel support according to Claim 6 wherein one hub is pinned to the shaft to provide an edge location for the web fed from or to the reel supported by the hubs.

8. A reel support according to Claim 1 or 2 or 4 wherein each hub is provided with an end disc acting as an edge guide to a web being fed from orto the reel supported by the hubs.

9. A reel support according to Claim 1 or 2 or 4 wherein one or both hubs is/are provided with a boss to which may be imparted drive or braking effort.

10. A reel support according to Claims 1 or 2 or 4 wherein each hub is provided with a chamfered nose to assistthe insertion of the hub into the bore of the core of the reel.

11. A reel support according to any preceeding Claim wherein the hubs for each end of the reel core are identical and interchangeable.

12. A reel support according to Claim 1 or 2 or 4 wherein the '0' ring is made from rubber or plastic having the qualities of natural rubber.

13. A reel support constructed and adapted to operate substantially as hereinbefore described with reference to Figure 1 or Figure 3 of the accompanying drawings.