GB2215711A

GB2215711A - Contactless web support guide

Info

Publication number: GB2215711A
Application number: GB8807170A
Authority: GB
Inventors: John William Ford; Maurice John Dyer
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-03-25
Filing date: 1988-03-25
Publication date: 1989-09-27
Anticipated expiration: 2008-03-25
Also published as: GB8807170D0; GB2215711B

Abstract

A contactless support guide as in GB 2194918, for guiding a moving web of material has an arcuate support face (22) containing shallow circular pockets (22a), and elongate pockets (22a) near the edges of the face, which contain air emission apertures (22b) and these pockets and apertures are angled towards the central region of the face. In the improved guide, in between each edge (92) of the face and the elongate pockets (22a) there are further blind pockets (90). <IMAGE>

Description

CONTACTLESS WEB SUPPORT GUIDE This invention relates to a contactless support guide for a moving web of material. The invention is related to UK Patent Application No 87 13 165 (2 194 918) hereinafter referred to as 'the aforementioned application'.

As described in the aforementioned application, a contactless support guide for a web of material comprises a web support face provided with a plurality of pockets and a pressurised air supply manifold for feeding air to the pockets. The pockets are in closely spaced relationship and the web is supported in spaced relationship to the support face by an air cushion which exhibits increased pressure at the web entry and exit regions of the support face. In a preferred embodiment, the guide further comprises an elongate pocket extending along each of the longitudinal edges of the support face at the web entry and exit regions, each elongate pocket being provided with a plurality of inlet apertures leading to a plenum chamber between the manifold and the support face.

In accordance with the present invention an additional pocket or group of pockets is provided adjacent one or both end margins of the support face relative to the exit and entry regions and this additional pocket or each of the additional group of pockets is blind and does not communicate directly with the manifold. Preferably an additional elongate pocket is provided adjacent each of two elongate pockets communicating with the manifold and parallel thereto. Each additional elongate pocket then lies between one of the elongate pockets and the end margin of the surface.

The invention may be understood more readily, and various other aspects and features of the invention may become apparent, from consideration of the following description.

An embodiment of the invention will now be described, by way of example only and with reference to Figures 6 and 7 of the aforementioned application and the accompanying drawing which is a cross-sectional view of a contactless support guide constructed in accordance with the invention.

Reference is made to, inter alia, Figs. 6 and 7 of the aforementioned application and to the description associated therewith. The guide shown in the accompanying drawing is a view equivalent to Fig. 7 of the aforementioned UK patent application and uses the same reference numerals. The guide differs from the earlier construction in having an additional elongate pocket 90 nearer each extreme end 92 of the surface 22 and adjacent the elongate pockets 22a. Unlike the latter, the additional pockets 90 are blind and do not receive pressurised air from the manifold 21. These extra pockets 90 improve the operational characteristics of the guide by creating static air pads at the extreme exit and entry regions. These pads appear to reduce noise, increase stability and make angular setting of the web less critical.

Claims

1. A contactless support guide for guiding a moving web of material; said guide comprising means defining an arcuate support face for controlling the moving web; a multiplicity of first pockets in the support face, the first pockets being distributed over the support face to substantially fill the face; second elongate pockets or groups of pockets provided in the support face at marginal regions where the web enters and exits the guide; a plurality of closely spaced apertures in each of the second pockets for emitting air; at least one further blind pocket disposed between one of the second pockets or group of pockets and adjacent an edge of the support face and an air supply means, including a manifold, for receiving pressurized air and for supplying said air to the apertures in the second pockets to create an air cushion extending around the support face to support the moving web in a generally uniform spaced relationship relative to the support face; wherein the second pockets and apertures therein are angled towards the first pockets.

2. A support guide according to claim 1, wherein a number of further blind pockets are provided between the edges of the support face and the elongate pockets.

3. A support guide according to claim 1 or 2, wherein the further blind pockets are also elongate.

4. A support guide according to claim 1, 2 or 3, wherein apertures are provided in at least some of the first pockets for emitting air.

5. A support guide according to claim 4, wherein the apertures in the first pockets are smaller than the apertures in the second pockets.

6. A support guide according to claim 3, wherein the second pockets and said at least one further pocket lie parallel to one another.

7. A support guide substantially as described with reference to, and as illustrated in, the accompanying drawing.