This invention relates to clothes driers. It concerns modifications applicable not only to the drier described in our International Application PCT/GB00/03254 (published as WO 01/14624 A), but to other rotary driers.
Figures 19 and 20 of that International Application show a wedging arrangement to help spread the arms at the start of the lifting process. A collar is drawn down towards the sleeve to which the lower ends of the arms are pivoted, and co-operates with wedge elements on the insides of the arms. Of course, after the initial downward movement of the collar, it reverses to go upwards with the sleeve while continuing for a while to act on the wedge elements. In the figures, a single part cord is shown, but it is suggested in the text that this could be doubled to form a purchase. However, while this eases the drawing together of collar and sleeve, the user still has to exert a considerable effort over the first part of the lift. Also, once the arms are fully raised, there is a long length of cord hanging down untidily.
It is the aim of this invention to reduce that effort and to have an automatic stowage of the tail of the cord at the end of the lift.
DE 19804608Cdiscloses a cable operated mechanism for raising umbrella arms from a fixed mounting on the support column which includes an internal weight supported on the cable to draw the loose cable into the column.
According to the present invention there is provided a rotary drier having a column, support arms pivoted to a sleeve slidable up and down 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, with lines between the 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 a draw cord coupling the collar and sleeve in a purchase arrangement enabling the collar and sleeve to be drawn towards each other, such that the collar co-operates with the wedge elements on the arms, whilst the sleeve is raised from its lowest position where the arms are retracted, so that the wedge elements cause the.arms to pivot away from the retracted position, characterised in that the draw cord is additionally led up and down into the column, which is hollow, to suspend a mass therein, the cord run being such that, on each side, one end of the cord is fixed to the sleeve, the cord is taken up over a first sheave or smooth fairlead on the collar, then down under a second sheave or fairlead on the sleeve, up again past the collar to the top of the column, over a thirds sheave or fairlead there, down under a pulley suspending the mass within the column, up over a fourth sheave or fairlead at the top of the column, down to the sleeve again, and finally out to the user from a fifth sheave or fairlead to a tail, such.that the mass will be drawn to and arrested at the top of the column when the draw cord is pulled, further pulling of the cord easing the lift of the sleeve up the column, and wherein release of the cord when the sleeve is raised allows the mass to descend and thereby recover the tail of the cord to the sleeve.
For balance, to avoid the collar and/or sleeve binding on the column, this cord arrangement may be doubled, with symmetry with respect to one diameter of the column. The sleeve, at least, will generally have a key and groove engagement with the column so that it does not rotate about the column.
For a better understanding, some embodiments of the invention will now be described, by way of example, with reference to the accompanying drawing, in which:
The drier has an upright hollow column 1, a sleeve 2 slidable thereon and with support arms (not shown) pivoted thereto between pairs of lugs 3, and a slidable collar 4 above the sleeve which acts on wedge elements on the insides of the arms as described in PCT/GB00/03264. The sleeve 2 (and possibly also the collar 4) has a key and groove engagement with the column (not shown) to prevent rotation.
Two diametrically opposed sheaves 5 are mounted in a cap 6 that plugs the head of the column 1, a single sheave 7 on the collar 4 and two diametrically opposed sheaves 8 on the sleeve 2. A draw cord 9 is fixed to the sleeve at 10 and it is rove successively over the sheave 7, under one of the sheaves 8, over one of the sheaves 5, under a pulley 11 suspending a mass 12 within the column, over the other sheave 5 and under the other sheave 8, its free end being attached to a toggle 13. This cord and pulley arrangement could be duplicated in mirror image fashion, the pulley 11 being doubled and the toggle 13 being common to both cords.
Initially, with the arms folded against the column 1, the mass 12 will have dropped a short distance down the column by its own weight, pulling the toggle 13 up to the sleeve 2, where it jams against the other sheave 8. The toggle 13 is pulled out from there to open up the drier, but at first the only thing that happens is that the mass 12 is pulled up to the top of the column where it or the pulley 11 is arrested by a stop that may be provided by the underside of the dome of the cap 6. Alternatively, if the cap 6 has a higher dome than that shown, the cord will stretch directly across between the sheaves 5. Continued pull on the toggle now has the effect of a multi-part purchase, drawing the sleeve 2 and collar 4 together and lifting those elements up the column 1. The support arms are caused to be wedged away from the column 1 and their expansion continues as the sleeve 2 is raised up the column. By the time the sleeve 2 is secure at its uppermost position there is a long length of cord 9 leading from the sleeve to the toggle 13. But once that toggle is released, the mass 12 is free to drop and it descends to about where the sleeve 2 was with the arms 3 folded before being arrested by the toggle 13 arriving at the sheave 8.
It will be seen that this arrangement gives not only a mechanical advantage simultaneously with the drawing together of collar and sleeve and with the lifting of the sleeve up the column, but also a solution to the stowage of the draw cord once the operation is complete.
There could of course be less sheaves and a shorter cord for lightweight driers, or more sheaves and a longer cord to increase the mechanical advantage with a large, heavy drier, but the arrangement of Figure 1 should be sufficient for most purposes.
It will be seen that the sheaves 8 are centrally mounted on upstanding lugs 14 of generally triangular form with rounded vertices. The sheave 7 is on a downwardly depending lug 15 with a centrally indented lower edge, the sheave being offset to one side of the indent 16. There is a similar lug diametrically opposite which will also carry a sheave if the duplicated cord version is adopted. As the sleeve 2 and collar 4 are drawn together the vertices of the lugs 14 locate in the complementary indents 16 and prevent mutual rotation. This also ensures that there is a true short vertical lead between the sheaves 7 and 8 when the arms are fully raised and so the cord 9 should run freely back into the column 1.
These interengaging lugs may also be used in the draw cord arrangement of PCT/GB00/03254, where there is no cord retraction, as illustrated in Figure 2.