EP0010928B1

EP0010928B1 - Take-up spool

Info

Publication number: EP0010928B1
Application number: EP79302330A
Authority: EP
Inventors: Peter Hugh Granby
Original assignee: Rank Organization Ltd
Current assignee: Rank Organization Ltd
Priority date: 1978-10-26
Filing date: 1979-10-25
Publication date: 1982-10-06
Also published as: GB2032884B; GB2032884A; DE2963820D1; EP0010928A1

Description

This invention relates to a take-up spool, more especially a take-up spool capable of reeling a strip of thin paper which issues from a printer or a strip of thin film.
When such a reel of paper or film bearing information is to be stored, it is necessary either to retain the complete spool or to be able to remove the wound reel from the spool. In the former case, it is a disadvantage that spare spools must be stocked by the user. Various proposals have therefore been made to permit removal of the reel from the spool, but hitherto no satisfactory solution has been found which does not result in damage to the strip at the innermost layers of the reel. This is because the reel must necessarily be relatively tightly wound for satisfactory storage, and when the mechanism of the printer does not itself produce a tight reel, it is conventional practice to tighten the reel by hand after removal from the machine.
Amongst various known proposals for radially expansible and contractable shafts, mandrels, arbors, rollers and the like is the arrangement disclosed in U.S. Patent No. 3,143,313.
This known arrangement comprises a moulded spool of two identical separable parts, and is specifically intended to carry a wound web of strip material, in particular the paper tape used in data processors. The spool is therefore axially relatively short. Each part comprises a circular cheek with a short axially projecting semi-circular hub portion. When the two parts are assembled together, the two hub portions define a circular hub adapted for connection to a winder tab for driving the spool. For supporting the wound paper tape, the cheeks carry respective fittings for supporting four arcuate spring arms which define a resilient mandrel of substantially greater radius than the hub. The said fittings include toothed abutments which cooperate with toothed portions of the spring arms, in use to lock the two parts of the spool against relative rotation, with the spring arms deformed radially outwards. When the two parts of the spool are unlocked, the spring arms are released inwardly. In practice, however, although the reduced diameter of the resilient mandrel facilitates removal of a reel to a certain extent, the innermost layers of the latter are liable to be damaged by the radially fixed fittings on the flanges, particularly the toothed fittings.
This disadvantage would be worsened if the known construction was employed for a spool of increased axial length.
From DE-C-946586, there is known a take-up spool having a basic structure which comprises two components having respective substantially non-resilient elongate portions of respective cross-sections such that their assembly in adjacent parallel relationship defines a generally cylindrical core on which a reel of said strip material can be wound by rotation of the assembled spool abouts axis, at least one of said components also having a portion through which a rotational drive can be applied, and said two components also carrying securing means which can be interengaged by a relative movement of the two components which completes assembly of the spool in the assembled condition, and wherein a reverse relative movement of the two components at the commencement of disassembly results in a reduction in the cross-sectional size of the core, thereby permitting disassembly of the spool from a reel wound on the core.
In this known arrangement, the securing means is a frictional structure with a non- positive locking action. There is therefore risk of accidental disassembly during use. This disadvantage can be overcome by the locking means disclosed in DE-A-21 57776, but the further disadvantage remains that the respective locking and unlocking action involves axial displacement between two axially tapering core portions in order to bring about the respective expansion and reduction of core diameter during assembly and disassembly. Especially on disassembly, the initial unlocking, axial displacement of the core portions within a tightly wound reel can cause damage to the inner layers thereof.
It is therefore an object of the present invention to provide a take-up spool which provides an improvement on the prior art, especially Patentschrift No. 946586, by permitting removal of the reel without risk of causing damage thereto.
The take-up spool of the present invention has the basic structure of the spool of Patentschrift No. 946586, and is characterised in that the securing means comprise two pairs of interengaging locking parts, one part of each pair and the co-operating part of the other pair respectively being carried at the opposite ends of the respective elongate portions forming the core, in that said locking parts are engaged by a relative rotational movement to complete assembly, thus producing a relative spacing-apart movement of the two core portions which thereby provides a slit between them for strip entry into the core, and in that said locking parts are disengaged by a reverse rotational movement which produces a relative closing-together movement of the two core portions which results in the reduction in core diameter on disassembly.
In a preferred arrangement, the two components are identical, each one component having an elongate core portion which projects axially from a flanged driving portion and carries, at its end remote from the driving portion, one of said two interengaging locking parts, the co-operating locking part being formed within the flanged driving portion of the other component. Conveniently, in this preferred arrangement, assembly of the two components is effected with their respective core portions effectively in contacting sliding relationship in the axial direction, and the driving portions of the respective components carry respective locating surfaces brought into engagement with the core portions as a result of the relative rotational locking movement of the two components, whereby said locking movement is accompanied by a lateral relative displacement of said core portions, without further axial displacement, into an expanded slightly spaced relationship defining a slit for strip entry into the core. It follows that, at the commencement of disassembly, the relative rotational unlocking movement of the two components disengages the core portions from the locating surfaces, permitting the core to collapse to a reduced cross-sectional size, without axial displacement of the two core portions.
A practical arrangement of take-up spool in accordance with the invention will now be exemplified with reference to the accompanying drawings, in which:-

Figure 1 is a side view of one of two identical spool components, the driving portion being illustrated in cut-away section;
Figure 2 is a plan view of the end of the core portion of the component remote from the driving portion;
Figures 3A, 3B and 3C serve diagrammatically to illustrate assembly and disassembly of two components which form a complete spool; and
Figures 4A to 4E are respective transverse cross-sections on the correspondingly marked section lines in Figure 1.

A preferred arrangement of take-up spool is assembled from two identical components each having the construction shown in Figure 1. This component comprises a portion 10 through which a rotational drive can be applied to the assembled spool, and an elongate portion 11 which, when assembled with the corresponding elongate portion of the other identical component, will form a generally cylindrical core for taking-up strip material to form a reel wound on said core. The axis of the component is indicated at 12.
The core portion has a ribbed construction as indicated in Figure 2, and at its free end remote from the driving portion 10 carries a locking means generally designated 13. The interior of the driving portion 10 is provided with a locking means 14 for interengagement with the locking means 13 of the other identical component. The locking means 13, 14 will be described in more detail later. Briefly, when the two identical components are assembled together, one with its driving portion on the left-hand side and one with its driving portion on the right-hand side, a final relative rotational locking movement of the two components interengages the respective pairs of locking means 13, 14 to complete assembly of the spool by locking the two components against relative axial movement and continued rotational movement. Disassembly may be effected by a reverse procedure.
The driving portion 10 comprises a hollow hub 15, a peripheral flange 16 which in use serves as a lateral edge guide for the strip being wound on the core, and a flanged portion 17 supporting a gear wheel 18. The driving portion could of course be differently constructed to enable a drive to be imparted in other known ways. The opening into the hub 15 on the axially inner face of the driving portion 10 is partly closed by the core portion 11 of the component, which forms an integral structure with the driving portion 10 and projects therefrom in a direction parallel to the axis 12. As shown in the cross-sectional view of Figure 4D, the core portion 11 has an arcuate cross-section extending over an obtuse angle somewhat less than 180 degrees. The driving portion 10 is thus left with an aperture 19 in its inner face which corresponds to a segment of a circle extending over an angle somewhat greater than 180 degrees, as shown in the cross-sectional view of Figure 4E. This aperture 19 receives the free end of the core portion of the other identical component.
The manner of assembly of the two components is indicated diagrammatically in Figures 3A, 38 and 3C. Figure 3A is a self-explanatory perspective view of the two components as they are brought together for assembly. At this time the relative angular orientation of the two components is to position the two core portions 11, 11 A with two lateral faces in contact, as shown in Figure 3B, in which 11 refers to the component with the driving portion on the left in Figure 3A and 11A refers to the component with the driving portion on the right. When the two components have been pushed fully together in the axial direction, assembly is completed by a-relative rotational locking movement of the two components, which twists the respective core portions 11 and 11 A into the relative positions shown in Figure 3C, in which the other two lateral faces of these core portions are in closely spaced relationship. As is clear from Figures 3B and 3C, the rotational. locking movement of the two components also produces a small lateral relative displacement of the core portions 11 and 11 A which expands the core to the cross-sectional size on which the reel is wound in use. The means by which this is done will be explained later. However, it will be apparent that, at the commencement of disassembly, a relative rotational unlocking movement in the reverse sense will collapse the core to a reduced cross-sectional size, thus releasing the core from the reel wound thereon and permitting complete disassembly to enable the reel to be removed. Figure 3C also shows that, in the locked condition of the assembled spool, the two core portions 11 and 11 A define a slot 20 enabling the leading end of the strip to be wound to be attached to the spool, without any special preparation of the strip.
It is also convenient to mention at this point that the arrangement is designed so that the relative rotational locking movement for completing assembly is effected in the same rotational sense as that in which the spool will be rotationally driven in use.
The locking means 13 and 14 will now be described. The means 13 consists of a radially- resilient generally axial extension 21 on the free end of the core portion 11. At its extreme end, the extension 21 has a shaped lateral projection 22 and just inwardly of this projection 22, a second shaped lateral projection 23 in radial alignment with the projection 22. The projection 22 is longer than the projection 23. The extension 21 has a reducing and varying cross-section towards its extreme end carrying the projections 22 and 23, and for better illustration of the shapes involved the parts 21 to 23 are shown in the cross-sectional views of Figures 4A, 4B and 4C. The locking means 14 comprises two angularly spaced axial grooves 24 and 25 on the inside wall of the hub 15 behind the aperture 19. The axial groove 24 (see Figure 4E) is shaped to match the above- described projection 22. During assembly, the projection 22 seats slidably in the groove 24 to assist axial guidance as the two components are pushed together in the axial direction. At this time the two core portions are relatively positioned as shown in Figure 3B. The two components are pushed together in the axial direction until a shoulder stop 26 (see Figure 2) at the leading end of the core portion 11 behind the locking means 13 comes to abut the inner end face of the hub 15 at the periphery of the aperture 19. At this time, the arcuately-shaped trailing end of the extension 21 has just entered the aperture 19, while the lateral projection 22, but not the projection 23, has passed right through the driving portion 10 to be positioned just behind the rear face of the hub.
The rotational locking movement of the two components brings the core portion 11 to abut a locating surface 27 formed by one end edge of the aperture 19. The core portions of the two components are thus shifted laterally apart, as well as being twisted, to assume the relative positions shown in Figure 3C. In this connection, and referring to Figure 4E, it should be noted that one end edge of the aperture 19 is disposed on a radial line through the axis 12 while the edge 27 is slightly displaced from the parallel radius. The rotational locking movement of the two components also brings the lateral projection 23 into seating engagement with the matching groove 25 on the inside wall of the hub 15, locking the two components against reversed rotation by virtue of the inherent resilience of projection 21. At the same time, the projection 22 engages behind the rear face of the hub 15, adjacent the rear end of the axial groove 25. This locks the two components against axial movement.
It will now be clear that disassembly can be effected by a relative rotational unlocking movement of the two components in the opposite sense to the locking movement. The core of the spool collapses to a reduced cross-sectional size during the unlocking movement, thereby to enable release of a reel of strip material which has been wound on the core, for example while the spool has been in use at the output of a printer. The reel is readily freed without damage to the inner layers, while the spool can then be re-assembled for further use.
It will be appreciated that various modifications are possible within the scope of the invention indicated in the appended claims. For example, the invention is applicable to other types of spool, including spools adapted to be rotationally driven in other ways and spools in which lateral guiding of the strip is rendered unnecessary by virtue of the provision of prior guides in the machine. In these and other circumstances, the use of two non-identical components may be desirable, and in its simplest form the spool may essentially consist of two core portions one of which is adapted to be rotationally driven, together with suitable interengaging locking means which, when unlocked, bring about a reduction in the cross-sectional size of the core without axial displacement of the core portions to facilitate release of a reel which has been wound thereon.

Claims

1. A take-up spool for strip material, comprising two components having respective substantially non-resilient elongate portions (11) of respective cross-sections such that their assembly in adjacent parallel relationship defines a generally cylindrical core on which a reel of said strip material can be wound by rotation of the assembled spool about its axis (12), at least one of said components also having a portion (10) through which a rotational drive can be applied, and said two components also carrying securing means (13, 14) which can be interengaged by a relative movement of the two components which completes assembly of the spool in the assembled condition, and wherein a reverse relative movement of the two components at the commencement of disassembly results in a reduction in the cross-sectional size of the core, thereby permitting disassembly of the spool from a reel wound on the core, characterised in that the securing means (13, 14) comprise two pairs of interengaging locking parts, one part (13) of each pair and the co-operating part (14) of the other pair respectively being carried at the opposite ends of the respective elongate portions (11, 11) forming the core, in that said locking parts are engaged by a relative rotational movement to complete assembly, thus producing a relative spacing-apart movement of the two core portions which thereby provides a slit (20) between them for strip entry into the core, and in that said locking parts are disengaged by a reverse rotational movement which produces a relative closing-together movement of the two core portions which results in the reduction in core diameter on disassembly.

2. A take-up spool according to claim 1, wherein the two components are identical, each one component having an elongate core portion (11) which projects axially from a flanged driving portion (10) and carries, at its end remote from the driving portion, one of said two interengaging locking parts (13, 14), the co-operating locking part being formed within the flanged driving portion of the other component.

3. A take-up spool according to claim 1 or claim 2, wherein the elongate core portion (11) of each component has a cross-section corresponding to an obtuse-angled segment of a circle (Figures 3B, 3C) and the driving portion (10) of each one component has an aperture (19) of shape generally corresponding to a circular segment covering an arc greater than said obtuse angle and for receiving the locking part (13 or 14) at the end of the core portion (11) of the other component.

4. A take-up spool according to claim 2 or claim 3, wherein the locking part (13 or 14) carried on the end of the core portion (11) of each one component comprises a radially- resilient generally axial extension (21) having a lateral projection (23) for seating in a recess (25) in an internal wall of the driving portion < 10) of the other component.

5. A take-up spool according to claim 4, wherein the said axial extension (21) carries two angularly aligned lateral projections (22, 23) and the said internal wall has two angularly spaced seatings (24, 25), the first projection (22) co-operating with the first seating (24) to assist axial guidance of the two components during assembly of the two components into co-operative relationship, and the second projection (23) being brought into engagement with the second seating (25) as a result of the relative rotational locking movement of the two components which completes assembly of the spool.

6. A take-up spool according to claim 5, wherein the first projection (22) engages behind the rear face of the driving portion (10) as a result of the relative rotational locking movement, thereby to locate the two components against relative axial movement.

7. A take-up spool according to any one of claims 1 to 6, wherein the driving portion (10) of each component comprises a hollow hub (15), a peripheral flange (16) for acting as a lateral edge guide for the strip to be wound on the assembled spool, and a driving gear (18) behind the flange.