GB2114355A - Adjustable display indicator - Google Patents

Abstract

An indicator for displaying a selected numeral 4 comprises a web bearing the numerals 0 to 9 at intervals along its length and wound between support rollers 2,3. The web bears an optical marking 14 for each numeral which is detected by a photo-electric device (15). The rollers are driven by a single motor 11 or a pair of motors (42, 43 - Figure 4) to move the web longitudinally to bring a selected numeral to a display position. As the web is moved it is stopped at the next numeral by sensing the optical marking 14. The web may pass around a third roller 46 freely suspended below the other two so as to maintain the web taut. A set of indicators can be mounted in a display unit (Figure 3) having an enclosure (30) whose front panel (32) has display windows (33) at each of which an indicator is mounted. One use of such units is for petrol price displays. <IMAGE>

Description

SPECIFICATION Adjustable display indicator This invention relates to an adjustable display indicator and has particular, though not exclusive application, to what will be called herein a multiindicator display unit. Indicators to which the invention is applicable find use in, interalia, price indicators, score boards, and advertising displays.

Numerical indicators find particular use in display units at petrol filling stations to show the price of petrol per gallon and/or litre. It is generally desirable that the displayed numerals be readily changeable for ease of adjustment in response to price changes.

In such a display unit each numeral is individually alterable, or at least those numerals which are likely to be adjusted the most frequently are individually alterable. Such display units are multi-indicator displays in that there is a plurality of individually adjustable indicators in the display. In this case each indicator is a single numeral but multi-character indicators are equally possible, for example for changeable advertising displays.

According to one aspect of the invention there is provided an indicator comprising a web bearing legends spaced at intervals along its length and respective means marking the position of each such legend, support means between which the web is traversable through a viewing window position, drive means for driving the web lengthwise in a selected direction and sensor means cooperable with said marking means to sense when the next legend is at the viewing window position for interrupting the drive means.

The legends borne by the web may for example be a series of single numerals, such as the numbers 0 to 9, that are individually selectable for display. Depending on the use of the display, legends may generally include single alpha-numeric characters or combinations of them, or any other signs appropriate to the end use.

The legends may be such as to be visible from both sides of the web. The web may be front or back lit.

The means marking the legend positions on the web may be optical cooperating with a photoelectric sensor. Operation at infra-red wavelengths may be helpful in avoiding interference from other light sources.

To change a legend on the indicator above defined the indicator may include control means that includes means for activating the drive means to drive the web in a selected direction, and means responsive to the sensor means to interrupt the driving of the web when the next legend is in the viewing window position. The control means may be provided as a separate unit connectable, as by plug and socket connections, to that one of a plurality of indicators used in a multi-indicator display unit that needs changing at anytime.

In another aspect of the invention there is provided a display unit comprising a panel or the like having a plurality of apertures defining display windows, an equal plurality of indicators mounted at one side of the panel, each indicator adjacent a respective display window, and each indicator comprising a web bearing display legends at intervals along its length and respective means marking the position of each such legend, support means between which the web is traversable past the associated display window to display a selected legend thereat, drive means for driving the web lengthwise in a selected direction, and sensor means cooperable with said marking means to sense the position of same for interrupting the driving of the web when the next legend is positioned at the display window, and control means connectable to the drive means and sensor means of each indicator and operable to selectively activate the drive means for driving the web in a required direction and to interrupt the driving of the web when the next legend is positioned at the display window.

The just-mentioned panel or the like may constitute one side of an enclosure in which the indicators are mounted, there being means within the enclosure for illuminating the display window positions of the webs.

In various indicator constructions described in more detail below, the aforesaid support means of an indicator comprises a pair of rollers to which the web is mounted so as to be wound up on one as it is unwound from the other. The drive is applied to the web through the rollers. In one arrangement the drive means includes a respective motor coupled to each roller (preferably a geared D.C. motor), and the above-mentioned control means is connected, or connectable, to selectively activate one or other motor in dependence upon the selected drive direction. In this case each motor is preferably coupled to its respective roller through a clutch device, such as a slipping clutch or a unidirectionally driving device.

In another indicator arrangement drive is applied to the web through both the rollers, and the drive means comprises a single reversible motor coupled to both rollers to drive same together.

These indicator arrangements and particularly the single motor drive version, may comprise a further roller traversed by the web in its passage between the support rollers and biased to maintain the web taut. The bias may be provided by the weight of this other roller.

In a preferred arrangement for maintaining the web taut, the rollers of the abovementioned pair are mounted one above the other and there is a further roller below the lower roller of the pair, the web extending downwardly from the upper roller of the pair to pass around the further roller and thence extend upwardly to the lower roller of the pair. The further roller is freely suspended to maintain the web taut by virtue of its own weight. Guide means may be provided for locating the roller while permitting vertical movement of it.

In order that the invention and its practice may be better understood, embodiments of it will now be described with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic perspective view of a single numeral indicator using a single reversible motor drive; Figure 2 is a control circuit for indexing the display web of the indicator in one or other direction; Figure 3 is a view of a multi-indicator display unit for displaying petrol prices; Figure 4 is a diagrammatic perspective view of a modified display using separate motors to drive the display web in one direction and the other; Figure 5 is a diagrammatic perspective view of another modified indicator, using a single drive motor and having means for ensuring tautness of the web.

In the figures like parts are represented by like reference numerals.

Referring to Figure la a web 1 is carried by upper and lower rollers 2,3 which are mounted one above the other for rotation in a frame not shown in this figure. The web carries a series of legends or indicia 4, consisting of the numbers 0 to 9, in a regular spacing. The web may be a single sheet or film of plastics material or may be made by connecting a series of individual plastic rectangles, each carrying a number. For petrol price displays it is preferred that the web present an opaque appearance in which the numerals are translucent by contrast. This can be achieved by overprinting a translucent web to leave only the areas defining the numerals translucent.

The web is mounted to the rollers in the manner of a roller blind, being wound from one to the other.

Each of the rollers 2, 3 carries at one end a sprocket 5, 6. The sprockets are interconnected by a toothed rubber belt 7. The lower roller has on its other end another sprocket 8 connected by a toothed rubber belt 9 to a sprocket 10 on the shaft of a motor 11. The motor is a small low voltage D.C. motor with the output shaft geared down from the armature. A fluorescent lamp 12 illuminates the legends 4 from the back. The lamp may be of the cold or hot cathode type.

The web 1 is formed with a series of holes or translucent areas 14, one for each legend, and spaced so that each in turn is aligned with a photocell 15, as the web is moved by the motor, when the relevant legend is in its correct display position. An infra-red lamp, not shown, on the side of the web opposite the cell, emits light which is received by the cell when any one of the holes 14 comes opposite it. This photo-detector arrangement may use visible light The lamp and photocell can be realised by use of a light-emitting diode (LED) and phototransistor.

In the motor control circuit shown in Figure 2 the photocell 15 controls a relay R1 through transistors TR1,TR2. Energisation of the photocell actuates the relay R1 to the OFF position indicated. A two-pole start switch SW1, which can be arranged as a rocker switch rocking from a neutral position to which it is biased, can be moved so as to connect poles 20, 21 to either a leftward or a rightward position. A reversing relay R2 is controlled by pole 21; connecting pole 20 in either leftward or rightward position actuates relay R1 to the ON position in which it supplies current to the change-over contacts R2A, R2B or relay R2. It will be seen that the motor can be actuated forward or reverse according as switch SW1 is actuated to leftward or rightward position, to energise or not respectively the direction controlling relay R2.When energised the relay holds on contact R2C and that as soon as the photocell senses that the next legend is in a viewing window position between rollers 2 and 3, it will stop the motor by bringing relay R1 to the OFF position.

Figure 3 shows a display unit arranged as a filling station pole sign giving the prices of 4-star petrol per litre and per gallon. There will here be seven digits requiring adjustment and therefore seven indicators, as shown in Figure 1,will be enclosed within a box 30 mounted on the pole 31. Conveniently the box is made with an aluminium frame and acrylic front and back panels approximately 60" x 40" x 15". The front panel 32 has a plurality of apertures 33 in it defining display windows and a respective indicator device is mounted at the inside of the panel to have its viewing window position coincide with the associated display window. The numerals are conveniently 12" x 9" and only one appears at a time. These dimensions are by way of example indicating typical requirements for a petrol price display. The web may be such as to show digits on either side.

While the motors through all the indicators may be separately controlled from, for example, the forecourt cash desk, this is not necessary and it may be sufficient to plug a control box containing the circuit of Figure 2 within the dashed line into appropriate sockets indicated at A,A and B,B for each indicator.

The indicators are then adjusted one at a time. It will be appreciated that the price indications will not need to be changed too frequently.

The indicator described could be adapted for a variety of purposes, for example, to indicate cricket scores or departure times, or to carry advertising material.

Figure 4 shows a modification of an individual indicator. The web or film 1 (no legend is shown) winds between the upper and lower rollers 2 and 3 which are shown rotatably supported in channel section side frames 40, 41. The rollers 2 and 3 are driven by respective small D.C. motors 42 and 43 geared down as in the previously described embodiment and coupled to the respective rollers by respective clutches 44 and 45. These may be frictional slipping clutches or unidirectional devices so as to not impede roller movement when the other motor is driven. The web is provided with holes or translucent areas 14, one to each numeral, for indexing the web and these cooperate with a photo-detector circuit (not shown) in the manner already described.

In the embodiment of Figure 4the control circuit of Figure 2 is adapted to connect contacts of relay R2 to energise one or other of the motors 42 and 43 in dependence on the direction of actuation of switch SW1.

A further modification of the indicator of Figure 1 is illustrated in Figure 5. The web 1 is wound between upper and lower rollers 2 and 3 rotatably mounted in side frames 40 and 41. The rollers carry sprockets 5 and 6 which are driven via toothed belt 7 from a single geared-down D.C. motor 11 fitted with a driving sprocket 10. The motor 1 is reversibly driven by means of the circuit of Figure 2. Each numeral carried by the web has an indexing hole or translucent area 14 associated with it for cooperating with a photo-detector arrangement (not shown) as previously described.

In this embodiment the guide frames extend at 40a and 41a substantially below the lower roller 3 and carry within the channel sections a weighted free roller 46 around which the web passes. Thus the web descends from roller 2 passes through the display window position and continues down to pass under roller 46 and thereafter ascends to roller 3. The freely suspended roller 46 ensures tautness of the display web by moving vertically to take up any slackness or contraction that would otherwise arise in the web. In particular it provides compensation for changes in the length of web between rollers 2 and 3 due to the changes in the diameter of the web rolls on rollers 2 and 3 as the web is wound, while allowing both rollers to be driven by the single motor. The channel sections locate the roller 46 against lateral movementwhile providing guides permitting vertical movement of the roller.

There may be advantage in some situations in order to avoid interference from other light sources, e.g. car headlamps, to have a photo-detector system sensing the optical markings 14 that operates at an a.c. frequency. In this case the lamp is a.c. energised and the detector is a.c. coupled for the required frequency through an amplifier and bridge detector to activate the transistors TR1 and TR2 of Figure 2.

The mains supply frequency is adequate in many case but a special frequency may be used to provide better isolation.

Claims (15)

1. An indicator comprising a web bearing legends spaced at intervals along its length and respective means marking the position of each such legend, support means between which the web is traversable through a viewing window position, drive means for driving the web lengthwise in a selected direction and sensor means cooperable with said marking means to sense when the next legend is at the viewing window position for interrupting the drive means.

2. An indicator as claimed in Claim 1 further comprising control means including means for activating the drive means to drive the web in a selected direction, and means responsive to said sensor means to interrupt the driving of the web when the next legend is in the viewing window position.

3. An indicator as claimed in Claim 2 in which said support means comprises a pair of rollers to which the web is mounted so as to be wound upon one as it is unwound from the other.

4. An indicator as claimed in Claim 3 in which drive is applied to said web through the rollers, said drive means including a respective motor coupled to each roller, and said control means being arranged to selectively activate one or other motor in dependence upon the selected drive direction.

5. An indicator as claimed in Claim 4 in which each motor is coupled to its respective roller through a respective clutch device.

6. An indicator as claimed in Claim 3 in which drive is applied to said web through both said rollers, and said drive means comprises a single reversible motor coupled to both rollers to drive same together.

7. An indicator as claimed in any preceding claim further comprising another roller traversed by the web in its passage between said support rollers and biased to maintain the web taut.

8. An indicator as claimed in Claim 7 in which the bias is the weight of said other roller.

9. An indicator as claimed in Claim 3 or 6 in which the rollers of said pair are mounted one above the other and further comprising another roller below the lower roller of the pair, the web extending downwardly from the upper roller of said pair to pass around said other roller and thence extend upwardly to the lower roller of said pair, said other roller being freely suspended to maintain the web taut by virtue of the weight of said other roller.

10. An indicator as claimed in Claim 9 comprising guide means for locating said other roller while permitting vertical movement thereof.

11. A display unit comprising a panel or the like having a plurality of apertures therein defining display windows and an equal plurality of indicators each as claimed in any preceding claim mounted at one side of said panel, each indicator being so mounted as to have its display window position, located at a respective display window of the panel.

12. A display unit as claimed in Claim 11 in which said panel or the like constitutes one side of an enclosure, said indicators being mounted inside said enclosure, and further comprising means within the enclosure for illuminating the display window positions of the webs.

13. A display unit comprising a panel or the like having a plurality of apertures defining display windows, an equal plurality of indicators mounted at one side of the panel, each indicator adjacent a respective display window, and each indicator comprising a web bearing display legends at intervals along its length and respective means marking the position of each such legend, support means between which the web is traversable past the associated display window to display a selected legend thereat, drive means for driving the web lengthwise in a selected direction, and sensor means cooperable with said marking means to sense the position of same for interrupting the driving of the web when the next legend is positioned at the display window, and control means connectable to the drive means and sensor means of each indicator and operable to selectively activate the drive means for driving the web in a required direction and to interrupt the driving ofthe web when the next legend is positioned at the display window.

14. An indicator substantially as hereinbefore described with reference to Figures 1 and 2, or Figure 4 or Figure 5 of the accompanying drawings.

15. A display unit substantially as herein before described with reference to Figures 1 to 3, or Figures 1 to 3 as modified by Figures 4 or 5 of the accompanying drawings.