With most driers of this kind, when the arms are folded against the column, by sliding the sleeve downwards, the lines hang in festoons around the column. They flap about unless a fabric cover is pulled down over the folded drier, and they can get in the way of the next person who raises the sleeve to spread the arms.

It has been proposed, for example in EP-B-0 113 788, to pull the lines into the arms as they are folded, keeping them tidy and making a fabric cover unnecessary. However, although that works, it is quite complicated with a multitude of sliders and a cord guided down each arm, out past the hinge to the sleeve and up the column to be attached near the top. EP-B-0 514 561 does away with those cords and relies on weights acting on or being provided by the sliders to pull the lines into the arms.

It is the aim of this invention to link the lines within each arm so that the movement of a single member can simultaneously pull all the lines into that arm. Another

separate aim is to facilitate the spreading of the arms, particularly at the start of that operation.

According to one aspect of the present invention there is provided a rotary drier having a column, arms linked to the column to be movable collectively between a retracted position alongside the column and a raised, in-use position radiating outwardly and upwardly from near the top of the column, lines between adjacent arms that come taut in a graduated set of 2n or 2n+1 polygons when the arms are raised, a yoke movable lengthwise of each arm, and strops coupling the corners of the polygons in pairs within the arms to each yoke, the rth outermost and the rth innermost polygon being linked by an rth strop that is rove around part of the yoke, and the central polygon, when there are 2n+1 polygons, being directly linked to the yoke, where r=1,2... n, and means for moving the yokes towards the roots of their respective arms to pull the lines into the arms when the arms are retracted.

Preferably each arm has a main arm member and a guide element carried thereby and shiftable longitudinally thereof, both having a set of registering apertures through which adjacent sections of each polygon enter the associated arm. The apertures may be configured so that, in one position of the guide element each pair of registering apertures creates two separate holes, each for a respective one said adjacent section, and in another position of the guide element each pair of registering apertures creates a single hole. This other position allows the junctions

between lines and strops to be pulled out clear of the arm for adjustment or when replacing lines, for example.

Conveniently, the apertures in the main arm members will be in sides thereof that face upwardly when the arms are spread and towards the column when the arms are folded.

Preferably, the guide element of each arm extends over said side and has divergent flanges along opposite edges.

The lines will run over these flanges when the arms are spread, and the flanges of all the arms will co-operate to enclose the column when the arms are folded. Thus not even short horizontal lengths of line between adjacent arms will be visible.

Conveniently, the yoke is a plastics moulding providing smooth surfaces under which the strops run and configured to keep the strops separate and balanced in relation to the attachment point of the moving means.

The moving means may be a spring within each arm, and preferably a constant force coil spring. This can be positioned at the root of the associated arm and have a straight line connection to the yoke.

In a simpler, less automatic version the moving means is a manually operable slider movable lengthwise of each arm. These sliders can have projections such as knobs or finger rings which are proud of the outer/under sides of the arms, in which case a main member of each arm is conveniently a generally channel shaped extrusion with the associated slider guided by formations at the mouth of the channel and with its projection extending outwardly beyond

that mouth. The sliders may be elongate to provide covers over the inner/lower ends of the channels when the arms are retracted, while the outer/upper end of each channel may have a permanent cap behind which most of the slider will move when the arms are extended to the in-use position.

According to another aspect of the present invention there is provided a rotary drier having a column, arms pivoted to a sleeve slidable up and down the column to cause the arms collectively to move between a retracted position alongside the column and a raised in-use position radiating outwardly and upwardly from near the top of the column, lines between adjacent arms that come taut when the arms are raised, wedge elements on the sides of the arms facing the column, a collar, also slidable up and down the column, above the sleeve, and means for drawing the collar and sleeve together, wherein the collar co-operates with the wedge elements so that, when the sleeve is raised from its lowermost position where the arms are retracted and the collar is drawn towards the sleeve, the wedge elements cause the arms to pivot away from that retracted position.

The means for drawing the collar and sleeve together preferably include a draw cord or line attached to one of the collar and the sleeve, and led through a fairlead on the other of the collar and the sleeve.

For a better understanding of the invention, some embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an elevation of a rotary drier,

Figure 2 is a diagrammatic longitudinal section of an arm of a rotary drier, showing connections between the drying lines, Figure 3 is a cross-section of an arm of a rotary drier, Figure 4 is a detail of the upper/inner surface of an arm in one condition, for servicing, Figure 5 is a similar detail, but within the arm in an in-use condition, Figure 6 is a side view of a central part of an arm and its attachment to a stay, Figures 7 and 8,9 and 10,11 and 12 show three spring retraction arrangements for pulling drying lines into an arm, Figure 13 is a side view of a preferred spring retractor, Figure 14 is a plan view of the retractor of Figure 13, Figure 15 is a plan view of a yoke to which the drying lines are linked within an arm and to be coupled to a spring retractor, Figure 16 is a cross-section on the line XVI-XVI of Figure 15, Figure 17 is a cross-section on the line XVII-XVII of Figure 15, Figure 18 is a cross-section on the line XVII-XVII of Figure 15, Figure 19 is a side view of a lower part of a drier, showing a slidable sleeve to which the arms are pivoted, SUBSTITUTESHEET (RULE 26)

Figure 20 is a side view similar to Figure 19, but with the sleeve raised slightly to start spreading the arms, Figure 21 is an elevation of a rotary drier with manually retractable lines in the in-use position, Figure 22 is an elevation of the drier of Figure 21 with its arms folded and lines partially retracted, Figure 23 is a perspective view of a slider with a yoke with which each arm of the drier of Figure 21 is equipped, and Figure 24 is a cross-section of an arm of the drier of Figure 21.

A rotary clothes drier has an upright column 1 of metal tubing, generally aluminium. A sleeve 2, conveniently of moulded plastics material, is slidable up and down the column and the inner ends of equi-spaced arms 3 are pivoted to it. In Figure 1 there are three arms, but there will usually be four. More than that is possible but unlikely.

A cap 4 at the top of the column has three stays 5 pivoted to it and these couple to respective arms at about their mid points. When the sleeve 2 is raised and locked by a catch 6 to the column, these stays 5 support the arms 3 in generally radial but upwardly inclined attitudes. This also brings taut lines 7 between adjacent arms 3, in a spider's web arrangement. The catch may lock in any of several closely spaced positions, to make the lines more or less taut. When the sleeve is lowered, the arms and stays fold in alongside the column.

This is a well-known and long-established form of

drier, and the following describes how the lines 7 can be retracted into the arms 3 when those are folded.

Referring now to Figure 2, each arm 3 has within it a set of couplers 8 to which the lines 7 are attached. Two lines enter the arm from corresponding positions on adjacent arms via respective apertures and are attached or linked to an associated coupler 8. Instead of four separate lines for each circuit of the drier, there may be just one line, with intermediate points being fastened or belayed to three of the couplers and the ends of the line separately attached to the fourth coupler. Alternatively, if the couplers are small rings, as shown, a single line made into a loop can pass through them. The line could then be pulled round occasionally, thus not subjecting the same portions to wear all the time.

Within each arm 3 the coupler 8 for innermost line 7a is linked by a strop 9 to the coupler for the outermost line 7h. Likewise the second innermost line 7b is linked to the second outermost line 7g by another strop 10. There are further strops 11 and 12 correspondingly linking the other four lines 7c to 7f, and 7d to 7e. The bight of each strop passes through an eye on a yoke 13 which can move freely along the arm and which by spring means pulls all the lines into the arm as that is shifted to the vertical. Various spring means and a preferred yoke are described below.

In order to facilitate separating the strops from the lines 7, the couplers may conveniently be snap hooks fastened to the ends of the strops. The lines would pass

through the closed eyes formed by the hooks and their keeps.

Referring now to Figure 3, each arm 3 is an assembly of extrusions, the main one 14 preferably being of aluminium and the subsidiary ones 15 and 16 of plastics material. The main extrusion 14 is of generally U-section, open outwardly when the arms 3 are folded upright and downwardly when the arms are spread. Its base 17 has apertures 18 at regularly spaced intervals and at the root of each side 19, on the outside, there is a smoothly contoured channel 20. The sides 19 have inwardly projecting flanges 21 at their free edges and internal ribs 22 and 23 of lesser extent, one pair 22 near the flanges 21 and the other pair 23 at the junc- tions of the channels 20 and the flat portions of the sides 19. The ribs 22 and 23 and the sides 19 guide the yoke 13.

The subsidiary extrusion 15 is for closing the mouth of the extrusion 14. It is a strip of arcuate cross-section with two barbed legs 24 on the concave side which engage behind the flanges 21 while the edges of the strip bear on the outside of those flanges.

The extrusion 16 is for guiding the lines 7 and providing a neat finish when the arms 3 are folded against the column. It is generally H-shaped in cross-section, but with the sides flared. The sides comprise small but thick flanges 25, shaped to engage the channels 20 and hold the extrusion 16 with its web 26 close against the base 17 of the extrusion 14, and larger flanges or wings 27 which sweep in outward curves to terminate with outside beads 28. These

beads meet when the arms are folded, to enclose the column, and the lines 7 run over them when the arms are spread.

The web 26 has apertures 29 formed at intervals to register with the apertures 18, these apertures combining to allow the lines 7 to enter the arm.

In Figure 2 the lines 7 are shown diagrammatically entering an arm at opposite sides, but it is also known to have two adjacent sections of line entering through a common aperture as in Figure 3. Both have their advantages: with two separate apertures there is less risk of entanglement, while with one it is easier to effect adjustments. Figures 4 and 5 show how there can be two apertures for normal use and one for adjustment.

Each aperture 18 in the base 17 of the extrusion 14 (shown in full lines) is of wide U-shape, the limbs of each U pointing down the arm and forming a tongue 30 extending into the aperture to about its mid-height (measured length- wise of the arm). Each aperture 29 in the web 26 of the extrusion 16 (shown in broken lines) is rectangular, extending transversely of the web 26, and registers with an associated aperture 18. But while the apertures 29 are of substantially the same width (across the arm), they are only half the height (lengthwise of the arm).

The mutual engagement of the extrusions 14 and 16 is such that the extrusion 16 can slide longitudinally between a raised position where each aperture 29 registers with the upper half of its associated aperture 18 and a lowered position where it registers with the lower half. But the

existence of the tongue 30 means that there are then two separate holes. The raised position enables lines 7 entering the arm in close proximity to be pulled out together to expose the associated coupler 8. Then adjust- ments can be made, for example to tauten the lines, before the coupler is dropped back in again. Then shifting the extrusion 16 to the lowered position provides for the separation of the lines 7 as they enter the arm.

It will be understood that the apertures will be radiused to give a smooth lead.

The sliding of the winged extrusion 16 to create one or two holes for the drying lines may be limited as shown in Figure 6. Each stay 5 from the top of the column 1 has a pivotal coupling 31 to a plastics moulding 32 that fits around the arm 3 as a fixed collar, being secured by a rivet 33 and providing a clevis to receive the end of the stay 5.

The strip 15 is actually two separate strips, one above and one below the collar 32. But the winged extrusion 16 is unitary, with the collar 32 projecting through a slot 34 in its web 26 and the legs 25. This slot is longer in the lengthwise direction of the arm than the width of the collar 32 in that direction. When the extrusion 16 is slid down for the upper end of the slot 34 to bear against the collar, there are two separate holes for each drying line. When a top cap (not shown) of the arm is removed (it may simply plug into the end of the arm) the extrusion 16 can be slid up to cause the lower end of the slot 34 to bear against the collar 32. There is then a single hole for each drying

line.

The arm is assembled by first combining the collar 32 and extrusion 16, and then sliding both down the extrusion 14 until the collar registers with the point at which it is riveted in place.

The extreme lower end of the arm is pivoted between two lugs 35 (see Figures 19 and 20) projecting from the sliding sleeve 2. The shape of the arm means that it is not necess- ary to crop external ribs and smooth the sides in order that its lower end should fit snugly between the lugs 35, or to have the lugs 35 wider apart to clear uncropped ribs and accommodate packing washers. The pivot axis, indicated by a chain-dotted line in Figure 3, traverses the channels 20 so that there is no obstruction by a pivot pin to the insertion of a preferred yoke retraction device to be described below.

Various spring arrangements for pulling the yoke 13 towards the root of its arm 3 will now be described.

In Figures 7 and 8 the base of the yoke 13 is attached to an elastic cord or band 36 which leads towards the root of the arm, underneath a fixed pulley 37, back up the arm to its outer end, round another fixed pulley 38, and then down the arm to a fixed point 39 at the root. The cord 36 is slightly tensioned in the retracted position of Figure 7, but as the arms are spread each yoke 13 is pulled up its arm by the lines 7 being drawn out of the arms. The cord stretches and increases in tension, but its purchase-like configuration means that its extension proportional to its

original length is not excessive and therefore it does not stretch beyond its elastic limit.

When the arms are folded in again, each cord 36 contracts to pull its associated yoke 13 back down the arm, drawing in the lines.

In Figures 9 and 10, the base of the yoke 13 is attached to a plain cord or line 40 which leads towards the root of the arm, underneath a fixed pulley 41 and back up the arm to an elongate helical spring 42. The upper end of this is fixed at 43 at the outer end of the arm.

This operates in a similar manner to the retractor of Figures 7 and 8 except that the expansion of the spring is within one straight leg, its characteristic allowing this without overstretch. The arm can be large enough or be formed or fitted with a longitudinal partition to keep the yoke 13 and spring separate.

In Figures 11 and 12, the base of the yoke is attached to a plain cord 44 which leads towards the root of the arm, underneath a fixed pulley 45, back up the arm to a movable pulley 46, and then down the arm to a fixed point 47. The pulley 46 is carried by the free end of a constant force coil spring 48 mounted within the arm at its outer extrem- ity. It resembles the spring to be found in a retractable tape measure, for example.

This arrangement is a 1: 2 reverse purchase where the travel of the yoke 13 is twice that of the pulley 46.

However, the coil spring 48 can be powerful, and the negative mechanical advantage is not a handicap. Indeed it

means that with no great extension required the spring can be small and fit easily within the arm, and the yoke 13 never meets the pulley 46 and risks entanglement.

But preferably a coil spring is fitted within the root of the arm with a straight line attachment directly to the yoke, thereby dispensing with pulleys, in an arrangement as shown in Figures 13 and 14. A reel 49 wound by a coil spring 50 is in tandem with a bobbin 51, the spring 50 being closest to the lower, inner end of the arm. The bobbin 51 is in two axially separated parts, the part 52 being aligned with and substantially matching the size of the reel 49, while the other part 53 is narrower and has a line 54 wound on it. The free end of this line is connected to the yoke 13. The spring 50 leads from the reel 49 diagonally across the arm, as shown in Figure 14, to wind on to the part 52 in a manner such that the reel 49 and bobbin 51 will counter- rotate. Conveniently the reel 49 and bobbin 51 are mounted within a box 55 with a flange 56 at the reel end. This will be a firm fit in the end of the arm 3, the flange 56 matching its outer profile both to locate the box and to provide a neat end closure for the extrusion.

When the arms of the drier are folded, most of the line 54 is wound on the part 53. But as the arms are spread, the line 54 is pulled, rotating the bobbin 51 as it unwinds from the part 53. The part 52 of course rotates with it and this causes the spring 50 to be pulled out from the reel 49 and wound around the part 52. The torque exerted on the bobbin 51 by the spring, which wants to rewind on to the reel 49,

keeps the line 54 tensioned. When the drier arms are folded again, the line 54 is pulled and rewound on the part 53.

The preferred yoke is shown in Figures 15 to 18. This takes the form of a rectangular box-like structure 57, whose side walls will be parallel to the sides of the drier arm in which it is confined. The two shorter walls 58 are spanned by a U-section channel 59 symmetrical to the longitudinal centre line and between the outsides of this channel 59 and the longer side walls 60 there are six webs 61, three each side and in a symmetrical arrangement. The under edges of the four outer webs 61 have enlarged and rounded beads 62 and the base of the channel 59 has a central, downwardly projecting loop 63.

The link lines 9 to 12 are led down through the yoke, under the beads 62 and then up again through the yoke, each passing through a separate aperture in the grid formed by the webs 61. The line 54 from the coil spring assembly will be attached to the loop 63.

Most rotary driers have two positions for the arms, one where they are retracted and folded up against the column, and the other where they are spread, to radiate outwardly and slightly upwardly from a collar slid to a point shortly below the top of the column. There is a locking arrangement to hold the collar in place, and sometimes this offers fine adjustment up the column to make the arms a little"flatter" and thus tension the lines strung between them.

It is proposed that the present drier should have an intermediate or maintenance position about half way between

these two basic position. This is simply provided by a detent in the column 1 to which the sleeve 2 can lock at an intermediate position up the column. The arms 3 will then be half spread and extend up at an acute angle to the column, preferably somewhere between 30° and 45°. But they will be held firmly in this attitude and it allows, in particular, defective lines to be changed using the access arrangement described above. The couplers 8 between the drying lines and the strops can be pulled out clear of the arm through the temporarily single holes and then discon- nected.

When the arms 3 are nesting closely around the column 1, vertical movement of the sleeve 2 alone will not be able to start spreading the arms: they need some help. Figures 19 and 20 show an arrangement for providing this.

The sleeve has a fairlead 64 for a cord 65 whose upper end is attached to a sliding collar 66 with an inverted generally frusto-conical portion 67. The lower end of the cord has a pull handle 68. At their lower ends, clear of the extrusions 16 (not shown in these Figures), the arms 3 each have a wedge element 69 on their inner/upper sides and these elements co-operate with the portion 67.

In the start position of Figure 19, with the arms vertical, the collar 66 is well above the sleeve 2 and opposite the tapered upper ends of the elements 69. When the handle 68 is pulled, the collar 66 is forced down and starts to wedge out the arms 3. The sleeve 2 can then be started up the column and while one hand pulls the handle 68

the other one may grasp the sleeve and push it up. The collar 66 continues to act on the wedge elements 69 and spread the arms, an intermediate stage being shown in Figure 20. As the arms 3 reach the fully spread position, the collar has progressively less effect and is eventually carried up the column 1 by the sleeve 2.

When this movement is reversed, the collar 66 can be left to its own devices. The sleeve 2, carrying the weight of the arms 3, slides down easily once the catch 6 is released, and the collar follows. If it tries to catch up with the sleeve, the wedge elements 69 arrest it. The geometry of the portion 67 and the elements 69 is such that the collar will be squeezed back into the Figure 19 position as the arms close around the column.

Instead of a single part cord 65, it may be doubled to make a purchase, being attached to the sleeve 2, passing up and over a pulley on the collar 66, and then down through the fairlead 64.

The extrusion 16 does not of course extend over the full length of the arm; it stops short before the wedge element 69.

Instead of automatic retraction of the lines into the arms, there may be a less sophisticated, manually operated arrangement as shown in Figures 21 to 24. The construction of the arms 3 is generally the same as described above.

The lines 7 are coupled in pairs as in Figure 2 by strops 9 to 12 which lead around a common yoke 70 substan- tially the same as the yoke 13. However, it is pivoted at

71 to a bracket 72 fixed to one end of an extrusion 73. The cross-section of this extrusion is generally Q shaped, but Figure 23 is somewhat diagrammatic. In practice, each flange 74 will be cranked in cross-section as shown in Figure 24. The projection 72 extends out from within the channel formed by the extrusion, and on the opposite side, and at the same end, there is a projecting knob 75. The bracket 72 and knob 75 may be an integral moulding with a slot that is entered by a cutaway central end portion of the extrusion 73. Each extrusion 73 is a slider which can move lengthwise of the associated arm 3 as described below. The flanges 74 of the slider 73 are a loose fit in the grooves formed by the flanges 21 and ribs 22. The extrusion 15 extends over the outer part only of the respective arm, beyond the collar 32. But it will be seen that the crank in the flanges 74 allows for the snap fitting of the extrusion 15 where there is an overlap with the slider 73, and the barbed legs 24 will hold the flanges 74 against the ribs 22.

The sliders 73 are fitted so that the knobs 75 are at the inner end, towards the sleeve 2. When the arms are spread, as in Figure 21,22, the sliders 73 are almost entirely hidden with the knobs 75 adjacent the collars 32.

The channels of the arms will be open below that.

When the sleeve 2 is lowered and the arms retracted to the Figure 22 position, the sliders 73 will not move. They will be quite light, and there will be plenty of friction between them and the ribs 22 and the extrusions 15. So initially the lines 7 will hang down in festoons as seen on

the left hand side of Figure 22. But then they can readily be retracted simply by the user pulling down on the sliders 73 using the knobs 75. When the knobs are at the roots of the arms 3 practically all of the lines 7 will have been retracted into the arms as seen on the right hand side of Figure 22 and there will just be short horizontal sections between adjacent arms, shielded by the wings 27.

It will probably be convenient for the user to pull down two opposite knobs 75 simultaneously, and then move around the column and pull down the other two knobs 75.

When the sleeve 2 is raised again, the lines 7 are pulled out automatically and the sliders 73 are pulled towards the outer ends of the arms 3.

In the retracted position, the sliders 73 close off the channels of the arms up to the collars 32, but there will still be a substantial overlap with the extrusions 15 beyond the collars so that the sliders 73 are kept with their flanges 74 bearing against the ribs 22.

It is quite possible to have a rotary drier operating on these principles, using strops coupling pairs of lines 7, with an uneven number of polygons of lines. The outer and inner ones are coupled as described to a common yoke, while the middle polygon is directly connected to the yoke in each arm by a single dedicated line. It can readily be demon- strated that the amount of each section of the middle polygon that has to be pulled into each arm in order to leave just a short horizontal span taut between adjacent arms corresponds to the travel of the yoke coupled to the

other lines by strops to both lines. The strops are all of equal length and to save providing a special one for the middle polygon, that can be coupled to the yoke by a standard strop doubled.

It might be assumed that the polygons have to be equally spaced. That is likely to be the most common arrangement, but it is not necessary. As long as there is symmetry in spacing either side of the middle polygon (with an even number) or on either side of the middle pair of polygons (with an even number) this system of strops to a common yoke from corresponding inner and outer polygons will work without leaving lines slack. For example, the spacing may have a pattern, for an eight polygon drier, a, b, a, c, a, b, a, where a, b and c are the distances between adjacent polygons.