The invention concerns a device to be used with cords to raise or lower vertically-operated curtains of various kinds such as those that are pleated or rouched, Venetian blinds and others.

It is known that curtains are pulled up and let down by cords which, fixed to a lower cross-piece, pass upward and across the curtain and, having first passed round means of transmission mounted on a headpiece placed at the top of the curtain, drop down again at one end of said headpiece enabling the user to work them as needed.

As it must be possible to raise the curtain for its whole length and as the ends of the cords that drop down at one end of the upper headpiece must reach hand-height, it fol¬ lows that when the curtain is pulled right up, most of the cord that the user pulls will lie on the floor, bearing in mind the ratio between length of curtain and distance be¬ tween the ends of the cords at hand-height and the level of the floor.

I ^* . Cord lengths obviously differ allowing for the fact that they are fixed at different points on the lower cross-piece in relation to the side from which they are pulled.

The curtain is fixed at the desired height by means of a mobile roller which, due to cord friction, moves in the direction of cord movement becoming wedged between an op¬ posing wall and the cords themselves, so fixing them. It often happens, however, that the roller gets out of place so that the cords cannot be fixed and may even be freed because of one overlying another.

With the sash system the cords may often press against

sharp edges and become broken.

The so-called 'snapdragon' system fixes them firmly but just because of this the cords are liable to wear out and break.

The above invention eliminates all these disadvantages as will be explained hereafter.

Subject of the invention is a device for working vertically operated curtains by means of cords fixed at the lower edge of the curtain and pulled passing, in doing so, through means of transmission placed on a headpiece at the top of the curtain. The upper ends of the cords pass round two or more opposing pulleys, one or more of which are supported by the curtain's headpiece and one or more by a carriage sliding axially in relation to said headpiece. To this carriage a chain is fixed and after said chain has passed round a means of transmission on the headpiece,oppo¬ site (in relation to the carriage) to the pulleys carried by the headpiece, it drops down to a position within reach of the user's hand. Therefore, by pulling said chain the carriage moves causing the curtain to be drawn up while, when releasing the chain,

_ movement of the carriage in the opposite direction (caused by the weight of the curtain) allows the curtain to drop.

Curtain movement is multiplied in relation to chain move¬ ment in a ratio the value of which differs according to the number of opposing pulleys mounted respectively on the head¬ piece and on the carriage, and according to whether the upper end of each cord is fixed to said headpiece or to said carriage. The value of said ratio is 2 to 1 if only one pair of pul- leys is used, 4 to 1 if there are two pairs of pulleys or 6 to 1 if there are three pairs of pulleys, or else 3 to 1

if the upper end of each cord is fixed to the carriage and so on.

It is possible to obtain alternative values of ratios between chain movement and curtain movement by making each cord pass once, or more than once, round the pulleys of a single pair. There may be one or more cords according to the width of the curtain, and they are fixed to the end of the lower cross- piece to which the curtain too is fixed, and possibly at in¬ termediate points. It is an advantage for the cords to be of a constant length as their lower ends are fixed to one of the ends of the cur¬ tain's lower cross-piece (at the end opposite to the position of the pulley mounted on the upper headpiece) and they are carried up to the top headpiece over means of transmission which, as the case may require, are mounted at the other end of the curtain's lower cross-piece or at intermediate points.

Fixing the curtain at different heights is done by means of a transmission block in which there is a downward-facing groove made inside a vertical channel whose end slopes slight- ly outward, the chain sliding in this channel. , The end of i ^• . the groove is smaller than the diameter of the little balls placed at regular intervals along the chain.

Therefore, if the chain is pulled at an inclination slightly sharper than that of the bottom of the channel, it can slide freely and the curtain can be pulled up or let down but if the chain is set vertically, one of the little balls becomes stuck in the end of the groove and the curtain is thus held firmly in the desired position.

The advantages of the invention are clear. There is no surplus length of cord that has to lie on the floor as the ratio between cord movement and curtain move-

ment makes it possible to pull the curtain right up without any part of the cord resting on the floor.

The above ratio means that curtains can be raised or low¬ ered far more quickly and easily. Length of the cords fixed to the lower cross-piece of the curtain being constant ensures simpler manufacture and in¬ stallation.

Adoption of a transmission block having a groove in the channel along which a chain, of the kind mentioned above with little balls along it, not only facilitates fixing and releasing the curtain but makes the whole operation simpler and more reliable.

The possibility of mounting the chain on the right or the left of the curtain using a second channel with groove sym- metrical to the first channel and on the opposite side of the headpiece, is a further factor in facilitating instal¬ lation.

All the above is of great benefit to the user who can thus fit curtains that are quick, easy and reliable to draw up and let down, also offering a variety of applications.

Characteristics and purposes of the invention w ll be made still clearer by the following examples of its execution illustrated by diagrammatic figures.

Fig. I. Pleated curtain with three cords and with the invented device, longitudinal section.

Fig. 2. The curtain in Fig. I, cut through, seen from above.

Fig. 3. Diagram of the system, perspective view.

Fig. 4. Transmission block for the chain used to work the curtain, showing the chain locked, perspective view. Fig. 5. Same as above with the chain moving freely.

Fig. 6. The above curtain with 5 cords, perspective view. Fig. 7. The curtain in Fig. 6 cut through, seen from above.

Fig.8. Venetian blind with two cords and invented device, perspective view.

Fig.9. Curtain that rouches when raised, with four cords and with the invented device. The pleated curtain 10 hangs from the upper headpiece .50 onto whose two ends blocks 11 and 20 are respectively forced.

The carriage 28 is fitted inside the headpiece.

Block 11 is a body of hard plastic material comprising a

'comb' with 14 teeth carrying a small transversal shaft 12. Small pulleys 13, free to rotate round said shaft 12, are placed between one tooth and another.

At the back end of the headpiece, behind the teeth, there is a horizontal diaphragm 15 in which five holes 16 are made.

The carriage 28 is a block of plastic material which also has a comb and teeth 31 between which are placed the pulleys 29 freely rotating round the small shaft 30 pressed in trans- versally in relation to said teeth 31.

There is a hole 35 in the rear wall of said carriage 28.

The cross-piece 38 at the lower edge of the curtain 10, contains holes 37.

Said lower cross-piece 38 is connected to the ₍ upper headpiece

50 by means of cords 17, 41 and 42.

Cord 17 passes through the hole 37 in the cross-piece 38 and is held there by a knot 40. When said cord has passed through holes made in the pleats 19 of the curtain and the hole 39 in the upper headpiece 50, it passes round the race on the pulley 13 in block 11, then round the race on pulley

29 in the carriage 28 and finally returns to block 11 passing inside the hole 16 where it is held by the knot 18. Cord 41, held in the lateral hole 43 of the lower cross-piece

38, passes through the central hole 44 in said cross-piece and from there to the central hole 45 in upper headpiece 50;

then, after passing round pulleys 46 and 47 in block 11 and in the carriage 28 respectively, it is held in said block 11 by means of a knot.

Similarly cord 42 starts from a hole at one end of the cross-piece 38, passes from hole 49 at the other end of said cross-piece and having passed round pulleys 51 and 52 in block 11 and in the carriage 28 respectively, it is then held in said block by the knot 53.

The block 20, placed at the other end of headpiece 50, serves to guide the sliding movement of the chain 21 working the curtain, said chain being then fixed at one end, in hole

35 in the carriage 28, by means of a knot 36.

When chain 21 is pulled to raise the curtain 10, cords 17,

41, 42, having passed round the pairs of pulleys 13-29, 46-47, 51-52, are made to slide for a length double that of chain 21. In block 20, made from a piece of plastic material, there is a longitudinal channel 22 aligned with headpiece 50, that connects with the transversal-vertical channel 24 in which there is a groove 26. If chain 21 is pulled diagonally outwards, it slides freely in channel 24 but if it is made to lie vertically, one of i ^* . ^J its balls 27 is stopped by the end of the groove 26 thus locking said chain and therefore the amount of vertically hanging curtain. By means of channel 23, identical to and symmetrical with channel 24, opposite the longitudinal channel 22, the cur¬ tain can be hung as desired with the chain on right or left. Figs. 5 and 7 show a curtain hung on five cords 60, 61, 62, 63, 64, a useful solution if the curtain is very wide. Fig. 8 illustrates application of the device to a curtain 70 with slats 71.

In Fig. 9 the device is used for a curtain 72 which rouches when raised.

Clearly, by doubling or increasing the number of pairs of pulleys contraposed between block 11 and carriage 28 further points of transmission can be created for the cords between said block and said carriage. Each extra pair multiplies the ratio between cord travel and chain travel and this will continually allow greater curtin sliding movement equal to the length of chain that also slides .