DEVICE FOR A ROLLING SIGN
The invention relates to a rolling sign of the kind pre¬ sented in the preamble of claim 1.
Such rolling signs are known in many different versions, such as purely manual signs, where the rolls are operated and the sign adjusted by means of a handle, or where the rolls are engine-driven, for example by electromotors. The purely mechanical sign has the great disadvantage that a person is required to adjust the sign every time a change has to be made, which therefore requires access to the ad¬ justment device of the sign. The known engine-driven rol¬ ling signs have the great disadvantage that the driving engines and the driving connections from the engines to the rolls require space in the sign, which often results in an unacceptable volume. By both kinds of rolling signs it is moreover a general problem to keep the sign face suitably tight, both when the sign has been adjusted and while it is being adjusted.
It is the object of the invention to present a device for a rolling sign to ensure that the sign face is always suit¬ ably tight, i.e. both during adjustment of the sign and in the intervals, and without the space requirements of this device being unacceptable.
This is achieved by designing the device according to the invention as presented and characterized in claim 1. The whole device for ensuring suitable tightness of the sign face is placed inside the two rolls, and even with a very long sign face, for example in the order 25 windings per roll, i.e. approx. 50 windings in all, suitable, uniform pulls are achieved in the face, both while the device is being adjusted and during intervals, and all the way from the one end of the sign face to the other.
By designing the device according to the invention as pre¬ sented and characterized in claim 2, a noiseless and de¬ pendable construction is achieved, which ensures suitable tightness of the face depending on the size of the sign, the material of which the sign face is made, how rapidly the sign must be able to change its text, etc.
By designing the device according to the invention as pre- sented and characterized in claim 3, further space is saved, since the driving engine too is mounted inside one of the rolls. One driving engine in one of the rolls is sufficient, since the energy stored in the springs ensures rapid and uniform change of signs. The spring mounted in each roll thus has two functions. Firstly, it contributes towards ensuring constant tightness of the sign face, and secondly it contributes towards establishing the operation of the sign in both directions, since during rotation of the rolls, a continuous exchange of energy is taking place between the electromotor and the two springs via the sign face, so that uniform operation of the sign face is achiev¬ ed all the way from the one end hereof to the other end.
In order to obtain sufficient tractive effort from a com- paratively small electromotor mounted inside the roll, and to obtain a suitable number of revolutions of the rolls during change of signs, the motor is coupled to the rolls by a gear system as presented and characterized in claim 4.
By additionally designing the device according to the in¬ vention as presented and characterized in claim 5, the space requirements are further reduced, since the gear de¬ vice too is mounted inside one of the rolls, namely in the roll, in which the driving engine is mounted. The whole driving device is thus mounted inside the rolls which support the sign face, and the driving device with the
electromotor is preferably mounted as presented and char¬ acterized in claim 6.
By designing the device according to the invention as pre- sented and characterized in claim 7, a method for securing the sign face is achieved, and in such a manner that at the same time the possibility is provided of exchanging a sign face easily and quickly, and so that the driving power is in a simple manner transferred from the two springs to the rolls.
The invention also relates to a rolling sign of the kind presented and characterized in claim 8. A rolling sign is hereby achieved, which requires absolute minimum space, and where driving connections and driving devices are well- protected inside the rolls, both against dirt, dust, humid¬ ity and against any outside mechanical influence.
By additionally designing the rolling sign according to the invention as presented and characterized in claim 9, the possibility is provided of producing a sign built of modules with signs and symbols, for example letters and/or figures, so that any text may be shown on the sign by suit¬ able electrical control of the individual roll units. A sign is hereby produced, which can be operated from a distance in a simple manner and which can also display any desired text or line of figures.
The invention will hereafter be explained in more detail with reference to the drawings, in that
fig. 1 shows the principle of the device for a rolling sign according to the invention,
fig. 2 shows an axial section of the driving roll in fig. 1, and
fig. 3 shows an axial section of the driven roll in fig. 1.
Fig. 1 of the drawing shows the device for a rolling sign 1 according to the invention and comprising a driving roll 2 with a built-in electromotor, and a driven roll 3. The internal structure of both rolls will be explained in more detail later with reference to figs. 2 and 3 of the draw- ing.
A sign face 4 is. secured to the rolls 2 and 3, and the in¬ formation to be displayed is shown in appropriate positions of display on the sign face. For clarity purposes fig. 1 of the drawing only shows four letters, A, B, C and D, in one position of display. It is obvious to anybody that on a sign face 4 of a suitable length, for example of several metres, the possibility is- provided of displaying informa¬ tion about for. example the stops of~a-public..transports—on. any other desired information. In the shown example, the sign face 4 is transparent with printed, coloured text 5. Behind the sign face is mounted a light source 8 with a re¬ flector 6, so that only that part of the sign face, which is to be displayed, is illuminated from behind.
Each of the rolls 2 and 3 is provided with a number of longitudinally extending slots 7 having a dovetailed cross section. In the shown example, there are three slots in each roll. The sign face 4 is secured to the rolls by means of one of the slots in each roll, namely the slot 7'. The sign face is fastened by being led down into the slot which is hereafter filled up with a strip of a suitable material.
The rolling sign should naturally be built into either a suitable cabinet, or possibly directly into for example the means of transport, in which it is applied, for example
into the front of a vehicle or possibly directly above the entrance.
Fig. 2 of the drawing shows a central, axial cross section of the roll 2, and fig. 3 shows a corresponding section of the roll 3, in that the roll 2 is a driving roll with a built-in electromotor, whereas the roll 3 is a driven roll without a motor.
Fig. 2 sketchily shows the roll 2 mounted between two hol¬ ders or side walls 12 having suitable recesses for the roll to rotate freely. The section is made so that it passes down through a slot 7, and the drawing moreover shows that the roll is a cylinder 11 with a small wall thickness. The cylinder 11 is preferably made of aluminium by extrusion and is hereafter cut off in suitable lengths. At the one end of the roll, to the right in fig. 2, is inserted a housing 24 comprising' flanges 23 for engagement with the slots 7, so that the housing 24 rotates simultaneously with the cylinder 11. Inside the housing 24 is mounted a re¬ tainer 14 for an electromotor 13 and a gear device 16, 17, 18, and a spiral 38, so that via the gear device the motor is engaged with an annular, internal t othed rim 19 in the housing 24, whereby the motor can rotate the housing 24 and consequently the cylinder 11. The gear device with the spiral 38 is self-locking; consequently, further locking means for retaining the cylinder 11 in a certain position are unnecessary. The motor 13 and the retainer 14 are secured to the cabinet of the sign or to another fixed re- taining member by means of retaining members 21.
In the cylinder 11 is also aounted a torsion spring 27 around a spring retainer or cylinder 28, in that the spring 27 is at both ends secured to a spring retainer 26, 39. The spring cylinder 28 is in the middle of fig. 2 terminated by a retainer 25 which by a suspension 22 is secured to the
housing 24. The spring retainer 26 is rotated through the gear which is explained below for exchange of energy by tightening or slackening of the torsion spring.
The spring retainer 26 at the one end of the spring is rotatable and is by a toothed gear, for example a planetary gear 30, 31, 32, 33, 34, coupled to a retainer 36, 37 which is secured on the cabinet or the like of the sign. The gear 30-34 gears down from 1:2 to 1:15, preferably 1:10, between the numbers of revolution of the cylinder and of the spring at the retainer 26, the result being that when the motor 13 rotates the cylinder, the spring 27 will be tightened by one revolution each time the cylinder has made ten rota¬ tions, if the gear ratio is 1:10.
By rotating the cylinder 11, energy is thus stored in the spring 27, which is used to partly keep the sign face tight, and to partly help rotate the cylinder 11, when it is needed.
Fig. 3 shows a driven roll which except for a pipe section 41 and a retainer 42 which take the place of the motor construction and the gear housing herefor, is identical with fig. 2. All corresponding parts thus have the same re- ference numbers. In the cylinder 3, the gear 30-34 prefer¬ ably has the same gear ratio as in cylinder number 2.
The driving engine 13 is preferably a motor which is con¬ trollable and by which the direction of revolution is easily turned. The sign is controlled by switching the power to the engine on and off, and this is for example controlled by suitable perforations or indications (not shown) in the edge of the sign face 4, and read by a photo¬ cell arrangement or the like. The edge indications may be designed in such a manner that all the time the photocell arrangement and the control circuit belonging to it senses,
which part of th ιign is within the field of vision at the moment, so that the speed of the motor can be adapted to the distance the sign has to move, when it is to be re¬ arranged to another desired position.