GB2373621A

GB2373621A - Scrolling display apparatus

Info

Publication number: GB2373621A
Application number: GB0107224A
Authority: GB
Inventors: Edward Maurice Pierce Butler
Original assignee: Powergraphic Displays Ltd
Current assignee: Powergraphic Displays Ltd
Priority date: 2001-03-22
Filing date: 2001-03-22
Publication date: 2002-09-25
Anticipated expiration: 2021-03-22
Also published as: GB2373621B; GB0107224D0

Abstract

A display apparatus, for example a light box 10, has a web 16 windable between a pair of parallel spaced rollers 12, 14. The web 16 carries display posters and is releasably attached to one roller 12. The other roller 14 is spring-loaded (92, Fig 4) to rotatably bias the roller 14 against movement of the web winding onto the one roller 12. This bias holds the web 16 taught and the degree of bias is sufficient to cause the other roller 14 to wind the display length of web 16 on the other roller 14 when the web 16 is released from the one roller 12. The other roller 14 is removably mounted for rotation and can be removed and exchanged with a different roller carrying different posters. The web 16 engages the one roller 12 by a claw (60, Fig 3b) attached to the web 16 engaging slots (56, Fig 3a) in the one roller 12. A controllable drive mechanism 20, for example including an electric motor, is coupled to the roller 12, 14. A control circuit 22 may be provided to control drive mechanism 20 and have an automatic and manual modes, switchable automatically when the light box 10 is opened, to aid the changing of the web and roller 14.

Description

Title : Roller Blind Display Apparatus This invention relates to a display apparatus of the kind in which material to be displayed is supported in or on a roller blind, and to components used in such a display apparatus.

Roller blind display apparatus is well known particularly for advertising purposes where a series of display items (referred to herein as "posters") supported on or integrated with a roller blind are selectively presented to a display window. A commonly used form of this apparatus is what is known as a light-box in which the display is back-lit. The light box conventionally comprises a housing in the form of a shallow rectangular tray - that is of shallow depth in relation to height and width dimensions-and a front panel area that defines a display window. This panel is usually fabricated as a door allowing access to the interior of the unit. The display material is carried on a roller blind wound between a pair of rollers rotatably mounted adjacent opposite sides of the tray, more usually the upper and lower sides so the display scrolls vertically. The housing contains backlighting for the material in the display window and selectively operable drive means for rotating the rollers. Light boxes are commonly of substantial size, say 2m x 1.5m, and are fixed to building structures or ground mounted as free-standing structures.

A problem arises with light-box installations in regard to changing advertising items. At best the changing of display items requires travelling to the site where a light box is located and replacing, some or all of the existing posters with fresh posters. Such work may often need to be done out-ofdoors in inclement conditions. Refurbishing a number of light boxes spread over an area with fresh display material is a time-consuming task and needs to be done with care.

A common practice is to provide the light box with a web acting as a carrier that is affixed to and wound on the rollers. This web may be

translucent to allow it to be penetrated by back-lighting. The posters or graphics as they are known, are then secured to the carrier, as by Velcro fastenings; releasable plastic"zips"or other releasable means. For Velcro fastenings the hook part is fixed permanently to the carrier and the loop part is fixed to the top and bottom of each display poster as required. Such carrier supported displays require a number of tasks to be undertaken to change the display material at a light box. Typically the changing of the graphics involves the following steps in a light box apparatus of the type currently supplied by Powergraphics Display Limited under the name "Rollavision" : 1) Open the door.

2) Switch the machine from automatic to manual control. Automatic control selectively displays graphics in a selected sequence-manual control allows the carrier to be scrolled.

3) Scroll to the poster to be changed to remove poster.

4) Remove the poster to be replaced.

5) Attach in its place the new poster correctly centred and aligned. This is not just for aesthetic appearance but is important as an incorrectly positioned poster may crunch up against the edges of the rollers.

6) Ensure that the new poster is tucked behind the poster guides. This is important or the sensors will not see the markers on the carrier with which the automatic operation is performed. Furthermore attempted operation in these circumstances will time-out the machine after 4 seconds and bring it to a stop.

7) Remember to switch the machine from manual back to automatic otherwise the display remains static.

8) Close the door.

If more than one poster is to be changed then steps 3) to 6) are repeated as often as necessary.

It has been found that most of the problems in this sequence of steps arise out of steps 5), 6) and 7). As already noted, this sequence may have to be performed in inclement weather, at any time of year. Step 5) in particular is difficult in some conditions.

There will be described hereinafter a cassette for loading posters and a light box (for non back-lit apparatus) in which it is employed, the combination providing the following sequence of steps to be performed by the person who is changing one or more posters on site: a) open the door b) press a button to scroll up or down the roll of posters on the machine to a"change cassette"position c) release the roll of posters from the top roller to allow a self-tensioning bottom roller to reel the remaining poster down and wind it on to the bottom roller (the cassette roller). d) unclip the bottom roller and remove it e) clip in a new bottom roller (cassette) pre-prepared with the new graphics, f) pull poster roll upwardly off the cassette roller and attach its leading edge to top roller

g) shut door-which puts the machine into the automatic mode.

This sequence overcomes the problems of the prior procedure particularly be eliminating steps 5) and 6) and 7). The whole system is easier to operate, and the whole scrolling and poster accuracy is improved, reducing failures or faults on site. The pre-preparation of a cassette of fresh poster material can now be undertaken at a central location for a group of light boxes and the removal and attaching of individual posters can be done under more convenient and congenial conditions.

Aspects and features of the present invention are set forth in the claims of this specification. In order that the invention and its practice may be better understood an embodiment of it will now be described with reference to the accompanying drawings in which: Fig. 1 diagrammatically illustrates a light-box of known type looking from the front with the door removed; Fig. 2 shows the upper (top) roller assembly used in the embodiment of the invention; Figs. 3a and 3b show a claw assembly for the poster carrier that is releasably engageable with the roller of Fig. 2 in the embodiment of the invention, Fig. 3b being a section of the member seen in Fig. 3a; Fig. 4 shows a lower (bottom) roller assembly used in the embodiment of the invention; and Figs. 5a and 5b show face and side views of a releasable bearing clamp for the roller assemblies.

The invention will be described in relation to a roller blind display of the light-box type unit in which the the display items (poster) are supported on a windable roller blind acting as a carrier. The individual posters may be secured to the carrier by means of Velcro fastenings. In the described unit the carrier is wound in a path extending directly from one roller to the other and moves vertically through a display window area. The basic structure of light-boxes is well known in the display/advertising furniture field and need not be described in detail. Fig. 1 diagrammatically shows a known light box structure and elements of its mechanism.

The light box of Fig. 1 has an upright, rectangular housing 10. Spaced horizontal, parallel rollers 12 and 14 are rotatably mounted adjacent the upper and lower end walls. A carrier 16 is windable between the rollers to be transported along a vertical path which extends adjacent a display window area 18 (chain line) of a front-door panel (not shown). A drive mechanism 20 engages the rollers to move and selectively position the carrier 18. The drive mechanism includes an electric motor drive and associated control circuit 22 which, in an auto mode of operation, is responsive to index marks 24 on the carrier to control the switching on and off of motor drive to the rollers to selectively cause posters to be located in the display window. The mechanical coupling to the rollers 12 and 14 is indicated by the fine chain lines. A timing circuit 26 in the control circuit of drive 22 or mechanical means, such as a continuously driven cam, associated with the circuit provides for a dwell time in the display window. This control of the carrier movement is by way of example. Other arrangements providing the equivalent result are possible.

The control circuit of drive 22 may include a switch 28 accessible when the door is open operable to switch the circuit between auto control and manual control when the display posters are to be changed. The circuit may

also include a time time-out facility stopping further operation in the event of a failure to sense index marks when the carrier is being transported.

The posters affixed to the carrier have to be correctly longitudinally positioned so as to be properly presented in the window area when selected and also they need to be properly aligned in the window area, e. g. not present a skewed appearance. They are not to foul other parts, such as guides of the apparatus (these other parts are not shown). A selected poster fills with window display area 18. As already discussed the prior practice has been to conduct poster changing on site with the attendant difficulties already outlined.

The description which follows will concentrate therefore on those changes to the design and structure of the light-box and its components which are relevant to the solution to the problems of the prior arrangements.

Figs. 2 to 5 relate to a preferred embodiment of the invention.

Figs. 2 and 4 show axial sections through the upper and lower roller assemblies of a light-box embodying the present invention. The upper roller is provided with means releasably engageable by means at one end of the carrier. The lower roller is spring-loaded to maintain tension on the carrier in normal operation and to retract the carrier to a position wound up on the lower roller when the upper end of the carrier is released.

Referring to the upper roller assembly 40 of Fig. 2, the roller comprises a tube 42, of aluminium for example, of circular cross-section and onto which the carrier (not shown in Fig. 2) is wound. The tube 42 is supported on respective identical bushes 44a and 44b at its ends. The roller is mounted for rotation about its longitudinal axis A-A. Looking at bush 44a, the end portion of tube 42 in which it fits is secured to the bush, as by pop riveting. The bush is axially apertured to receive a drive pin 46. The bush is mounted to rotate with the pin by means of a flange member 48 secured to

the pin 46 and screwed to the bush 44a. The pin 46 projects axially away from the end of the tube 42 and the outer end receives a gear 50 secured to the pin 46 with a key, keyway connection to locate the two. The pin is supported for rotation within a bearing 52 releasably supported in fixed structure of the unit (not shown) and described below with rference to Figs. 5a and 5b. The bearing is axially positioned to abut the gear 50 by a spacer 54 whose other end engages the bush 44a. The bush 44b at the other end of the tube 42 is similarly constructed and supported. The gear wheel mounted to each drive pin may be driven by further gearing not shown and the whole assembly rotated by a single drive motor with the aid of one or more toothed drive belts or chains or similar.

The wall of tube 42 also has a plurality of aligned, spaced, axiallydirected slots 56 which are releasably engaged by claws of the carrier as will be described below with reference to Figs. 3a and 3b. It is presently preferred to use four aligned slots. A second row of four aligned slots may be provided in the tube wall offset at 900 from the row shown.

The carrier 16 to be wound between the upper and lower rollers of the light box (Fig. 1) is a web of strong plastics material, and is usually transparent or translucent to allow for back-lighting of the posters by lamps mounted at the rear of the light box. The upper edge portion of the web is secured to the claw device shown in Figs. 3a and 3b. The device is a member 60 of sheet material (metal such as aluminium or plastic) formed into an arcuate shape (Fig. 3b) extending a little less than 900 and having an internal radius that enables it to seat snugly on the surface of the roller tube 42. Along the upper edge 62 of member 60 are projecting portions 64 that are inwardly turned through about 1200 to form an internal acute angle with the upper edge 62. The portions 64 are axially dimensioned and spaced to match the axial dimensions and spacing of slots 56. Thus in this embodiment there are four claw portions 64 that are received in and engage

with the edges of the four slots 56. The acute angle with the upper edge enables the claws to be readily entered through the slots and then to securely hold on the slot edges in operation while being readily releasable when the carrier is to be changed. The top end portion of the carrier is received over the outer surface of member 60 as indicated by dash line 16'in Fig. 3b and is secured thereto by adhesive or pop-riveting.

The lower roller assembly 70 shown in Fig. 4 has some features in common with those of the upper roller but has important differences.

The roller 72 of assembly 70 is a tube like tube 42. It is rotatable about its longitudinal axis B-B. Tube 72 is supported at its ends on respective bushes 74a, 74b inserted in the ends and secured to the tube 72.

Drive to tube 72 is not applied through the bushes 74a, 74b but through a drive shaft 76 which extends the full length of tube 72 and which is rotatable within bushes 74a, 74b and coupled to the tube through spring-loaded coupling 90. The shaft 76 projects axially from the tube at each end but is driven at one end only-the left-hand end in Fig. 4. Looking at the bush 74a, it is centrally apertured for passage of the shaft which is rotatable relative to the bush and to this end a bearing 77 acts between the two. The outer end of the shaft 76 carries a gear 80 secured to it with a bearing 82 releasably supported in fixed structure as described below with reference to Figs. 5a and 5b. A spacer sleeve 84 acts between the bearing and the bush 74a similarly to the arrangement of Fig. 2. The gear 80 is preferably coupled to other gearing and drive applied through the same toothed belt or chain that couples to the left-hand side of the upper roller assembly 40 of Fig. 2.

The shaft is likewise supported through a bearing 82'for relative rotation in bush 74b, with the exception that no gear is provided on the righthand end of shaft 76 (as seen in Fig. 4). The shaft is axially located and held by a washer and clip 86 affixed on the shaft 76.

The carrier 16 (Fig. 1) is not shown in Fig. 4. Its lower end portion is secured to the tube 72, for example by pop rivets. It could be releasably secured but this is not a necessary feature. The intention is that the lower roller assembly is removable with the carrier and poster displays mounted thereon as a cassette unit replaceable by a fresh cassette. Before describing the spring coupling 90 in the lower roller assembly, the following should be kept in mind. When drive is applied to transport the carrier upwards (wound on the upper roller 42 and wound off the lower roller 72), as well as applying an appropriate drive polarity to shaft 76 (clockwise as seen from the right of Fig. 4), the tension in the carrier provided by rotation of the upper roller will also act to rotate the lower roller in the same clockwise direction. The spring tension of coupling 90 acts to rotate the roller tube 72 counter-clockwise with respect to the shaft 76 (as seen from the right of Fig. 4). This aids in maintaining the carrier taut in the display window and also acts, when the carrier is released from the upper roller, to draw the carrier downwards and wind it up on the lower roller.

Turning to the spring-coupling 90 in Fig. 4, it comprises a helical spring 92 extending about and along a portion of shaft 76 with tube 72. One end 94 is fixed to rotate with tube 72: the other end 96 is secured to a collar 98 in turn secured on shaft 76. In the embodiment illustrated the spring end 94 is secured to the bush 74b to which the tube 72 is itself fixed. The helical spring is wound about axis B-B to provide the required carrier tension. As will appear further below on putting a fresh cassette in the display unit, it is required to pull the outer edge portion (with the claws) of the carrier upwards which action will wind the spring 92 in the required direction.

Because the lower roller assembly is to be removed as an entity from the display unit, provision is made for ease of removal and replacement. To this end a first measure taken is that the gear 80 is not driven directly by the toothed belt but is driven by a sprocket wheel which it engages and which is

positioned so that the gear 80 can be lifted away from the sprocket wheel.

The latter is rotatable with another gear wheel driven by the toothed belt, chain or similar.

A second measure is to make the bearings 82 and 82'releasable from the fixed structure in which they are supported. The bearings are supported in releasable clamps such as shown in Figs. 5a and 5b. Each clamp 110 has an aperture 112 in which a bearing is receivable. The aperture is in two halves, one being in a portion 114 fixed with respect to the display unit housing, the other being in a portion 116 pivotally mounted with respect to portion 114 about pivot 118 to allow the aperture to be opened for release of the bearing and withdrawal from the portion 114. The two portions are secured to grip the bearing by a manually-operable releasable latch device 120.

The same measures as regards the gears and the support of the bearings can be applied to the upper roller assembly to assist in the ease of assembly and in subsequent maintenance should that prove necessary.

The same form of releasable clamp is conveniently used for supporting the upper and lower rollers. For cassette changing of the lower roller assembly, the upper roller remains in position. Each clamp as shown in Figs. 5a and 5b may be locked closed by means of a bolt 122 threadedly engaged in portion 116 and having a projecting end that engages in the threaded bore 124 of portion 114. Such an arrangement could be applied in the clamps for the lower roller without locking them but serving to act to accurately locate the two portions. In this case a locating pin is secured in portion 116 (corresponding to bolt 122) and projects to enter an unthreaded blind bore 124 in portion 114.

In order to promote quick and reliable substitution of the roller/carrier/poster cassette, an additional feature is added to the operation to the control circuit of drive 22 in Fig. 1. The switch 28 is made to be actuable by the door of the light box. When the door is closed the switch puts the machine into its automatic mode of operation. The opening of the door actuates the switch to cause the machine to be put into a manual mode of operation allowing pressing of a button to scroll down the carrier onto the lower roller. The scrolling operation may be initiated directly by the switch 28 upon opening of the door.

Claims

Claims 1. A display apparatus comprising: first and second parallel, spaced rollers, a web windable between the first and second rollers, a display area adjacent the path of the carrier for receiving a selected portion of the carrier adjacent the display area, controllable drive means coupled to said first and second rollers and selectively operable to position a selected portion of the web adjacent the display area, characterised in that one of said first and second rollers and one end portion of said web are engaged by releasable attachment means, the other of said first and second rollers includes a spring or elastic arrangement acting to tension the carrier and capable of causing the winding onto the other roller of a length of web at least substantially equal to the length of said carrier path between the rollers, and the other of said rollers is releasably mounted for rotation in the display apparatus to enable the other roller and the carrier wound thereon to be removed from the display apparatus.
2. A display apparatus as claimed in Claim 1 in which said one and said other rollers are upper and lower rollers respectively.
3. A display unit as claimed in Claim 1 or 2 in which said releasable attachment means comprises at least one slot in said one roller and a

claw member secured to said carrier and engaged in said at least one slot.
4. A display apparatus as claimed in Claim 1,2 or 3 in which the other of said rollers comprises an assembly having a tubular member for receiving said web, a drive shaft having a portion extending axially within said tubular member, said drive shaft being coupled to said tubular member by a helical spring about said drive shaft portion, said helical spring having one end connected to said tubular member and the other end connected to said drive shaft.
5. A display apparatus as claimed in Claim 4 in which said drive shaft extends through said tubular member to project axially outwardly at each end thereof, each projecting portion of the drive being mounted in a respective support bearing that is manually-releasable to allow withdrawal of the other roller assembly from the apparatus.
6. A display apparatus as claimed in Claim 5 in which each manually releasable bearing comprises a structure defining a bearing aperture, said structure being in two parts pivotally mounted to one and other, and movable between a closed and open positions, and a manually releasable latch acting between said two parts to retain them in the closed position and actuable to enable them to be moved to the open position for withdrawal of the drive shaft.
7. A display apparatus as claimed in Claim 4,5 or 6 in which said drive shaft carries one gear engaged with another gear driven by said drive means, the one and other gears being so mounted and positioned as to allow withdrawal of the drive shaft carrying the one gear from engagement with the other gear when the other of said rollers is to be withdrawn from the apparatus.
8. A display apparatus as claimed in any preceding claim in which said controllable drive means includes a control circuit and a switch actuable to cause the drive means to wind said carrier onto said other roller to a position at which said carrier may be disengaged from said one roller by said releasable attachment means.
9. A display apparatus as claimed in Claim 8 further comprising a door openable to allow access to said other roller and said carrier, and said controllable drive means includes a switch actuable upon closure of the door to put the drive means into an automatic mode of operation for presenting selected portions of the carrier at said display area.
10. A display apparatus as claimed in any one of Claims 1 to 7 further comprising a door openable to allow access to said other roller and said carrier, and said controllable drive means includes a switch actuable upon closure of the door to put the drive means into an automatic mode of operation for presenting selected portions of the carrier at said display area.
11. A display apparatus as claimed in any one of Claims 1 to 8 in which said apparatus comprises a door having a window providing said display area and said carrier path extends adjacent said window.
12. A display apparatus as claimed in Claim 9 or 10 in which said door has a window providing said display area and said carrier path extends adjacent said window.
13. A roller assembly for use in a display apparatus as claimed in Claim 1 in which the roller assembly is constructed in accordance with the construction of said other roller as set forth in any one of Claims 1,4 and 5.
14. A roller assembly for use in Claim 1 in which the roller assembly is constructed in accordance with the construction of said one roller as set forth in Claim 3.
15. A carrier for use in a display apparatus as claimed in Claim 1 in which the carrier has at least one claw member secured to an end portion thereof for engaging at least one slot in said one roller.