GB2170704A - Shortenable umbrella frame - Google Patents

Abstract

The invention relates to a frame for a telescopic umbrella having a slider (3) movable on a stick (1) and canopy supporting forks which are to be opened and closed by the slider and which are provided in a star-shaped arrangement around a crown (2) fitted on the stick and around the slider. In each case a link parallelogram is actuated by a scissors lever drive for the control of the folding motion of peripheral canopy spokes (10). In order to enable the canopy supporting forks to be more stable in their middle region, which is sensitive to deformation or rupture, and in particular to make it more resistant to excessive strain by gusts of wind causing the canopy to turn inside out, a hinge (9) connecting the inner canopy strut (7) to the control strut (11) in the open position of the umbrella canopy lies adjacent to the diagonal of the link parallelogram and bears against the bottom edge of a supporting strut (8) so that the link parallelogram appears as a flat triangular formation (T) having an obtuse outer angle ( alpha ), the hinge of the link parallelogram, connecting the supporting strut (8) to a short arm (10) of the peripheral canopy spoke, adopts from above about the same distance from the diagonal as the hinge connecting the inner canopy strut to the control strut adopts from below. <IMAGE>

Description

SPECIFICATION Shortenable umbrella frame The invention relates to a telescopic, or otherwise shortenable, umbrella frame having a stick with a fixed crown, a slider and a plurality of inner canopy struts each hinged at its inner end to the crown, each inner canopy strut crossing, and being connected by a scissors hinge to, a respective supporting strut which is hinged at its inner end to the slider, a scissors handle portion of each inner canopy strut extending outwards beyond the scissors hinge and being hinged to the inner end of a respective control strut which extends outwards beneath the supporting strut, and a plurality of peripheral canopy spokes each of which is hinged to the outer end of a respective one of the control struts and has, inwardly of this latter hinge, a short arm hinged to the outer end of the supporting strut, whereby the scissors handle and short arm form short links, and the control strut and the portion of the supporting strut above the condrol strut form long links, of a link quadrilateral. Such a frame is hereinafter referred to as of the kind described.

Umbrellas of thins design, which is distinguished, say, as compared with the widely practised design having parallelogram kinematics in accordance with BE-A-423344 or US-A-34671 15, by scissors actuated parallelogram-folding kinematics of the canopy spokes arranged in the peripheral region, are already known from, for example, Us-A-i 77339 and 180119. Umbrellas according to these latter specifications can be shortened into small-volume formations, and by the actuation of the slider, make use at the same time of a continuous complete folding of the canopy cover at one pull. In spite of their, in themselves perfectly stable structure, in strong gusts of wind, turning of the umbrella canopy inside out with the dome pointing upwards cannot be avoided.Because of the excessive loading caused in that case, and in particular of the tensile and compressive stress loading the sensitive middle region, this leads to deformations or even total destruction of the canopy spokes or the hinges. For the avoidance of the destructive turning inside out of the umbrella canopy, according to US-A-i 77339 threads are provided, which secure the opened canopy spokes to the umbrella handle. But in fact this measure does not prevent the turning inside out of the umbrella canopy and furthermore the tension threads for the restraining of the canopy spokes are in the way when carrying the open umprella. For that reason the production of this otherwise seemingly not impracticable design of umbrella has also up to now not been commercially acceptable.

The object of the invention is to create an umbrella frame of the kind described, which satisfactorily endures even turning inside out of the open umbrella canopy by gusts of wind without deformation or descruction of the canopy spokes and their hinges, where preventive measures demand minimum outlay and the canopy, which has been turned inside out, can easily be restored by returning the slider into its normal position.

This problem is solved in accordance with the invention in that the hinge connecting each inner canopy strut to the respective control strut lies, in the opened position of the frame, adjacent to the diagonal through the scissors hinge of the link quadrilateral and lies adjacent to the bottom edge of the supporting strut so that the link quadrilateral appears as a triangle with an obtuse angle adjacent to the hinge between the support strut and the short arm, and the hinge connecting the supporting strut to the short arm adopts from above substantially the same distance from the diagonal as that connecting the hinge connecting the inner canopy strut to the control strut adopts from below the diagonal.

In this way an umbrella is created, having essentially link parallelogram kinematics moved by a scissor lever-drive, of the kind described, which withstands even high wind forces and which, in the event that, through excessively high strain pressure, resulting from gusts of wind, the canopy does indeed turn inside ut upwards, but it does not then become deformed or destroyed. This results from the closely adjacent positioning effected with the canopy open, ofthe hinge between the scissors handle of the inner canopy strut and the supporting strut, just underneath the line of dead centre, i.e. the diagonal of the linkage as well as from the association of the hinge between the short arm of the peripheral canopy spoke and the supporting strut at about the same short distance with respect to this diagonal line.From that there results an opened canopy shape, the scissors lever arms and link parallelogram of which appear rather like a flat triangular formation which braces itself mutually in a stabilizng manner up to a locking position with the parts lying largely against or even in one another. If the canopy, nevertheless, does turn inside out because of far too strong a wind pressure, the link of each quadrilateral forming the scissors lever arm integrated into it, comes to lie just in front of the aforesaid diagonal, entirely in the locking position against or in one another, along with a brief buckling (resulting inter alia from the bending strain in the parts and through the play in the hinge bearings) of the outer side of the links which has not yet completely come up to a stop against the control strut with the formation of a second fixed stop.

Through these two fixed stops a total blocking position results and largely a self-stabilization of the middle region of the canopy, which is in danger of deformation or rupture, with the consequence that considerable tensile forces are led away into the less endangered flexible outer region of the canopy. The residual buckling of the outer side of the links for formation of the second stop and the completed locked bearing position is effected gently via swing of only a few degrees by the short arm of the peripheral canopy spoke. The residual stress movement of the fork mechanism in the middle region of the canopy upon the dome of the canopy becoming inverted upwards is therefore kept as small as possible.Since the locking position is effected in front of the aforesaid diagonal line, a sideways twist through, and shearing out of line of, the links is at the same time avoided and thereby finally once again deformation or destruction of the canopy spoke or of its hinge. Through the aforesaid design and arrangement of the canopy kinematics the latter may, in particular, through the aforesaid dead-centre stabilization stops and bearings, once more without excessive stress or deformation or rupture, and simply through pulling down the umbrella slider on the umbrella stick, be restored out of the upwards inverted doming into the regular canopy doming again.In doing this the length of shift to the covered by the umbrella slider is comparatively short, since the opening scissors action by the inner canopy strut and the supporting strut proceeding from it, after a comparatively short moment of overcoming stress, releases the necessary reversal togglepoint of the peripheral canopy spokes via the link quadrilateral lying blocked off in one another. For the realization of the invention, no additional technical outlay is needed as compared with the basic concepts which may be derived from the old models mentioned initially.

A particularly stress-resistant and operationally reliable refinement of the invention results if the one short link of the link quadrilateral, forming the scissors handle, consists of a fork which supports and guides the scissor-hinge, the supporting strut and its own connecting hinge; and if the other short link ofthe link quadrilateral, formed by the short arm of the peripheral canopy-spoke, at one end, by means of a further fork, guides the upper long link of the link quadrilateral to be able to rotate at the hinge, and, at the other end, in its connection to the lower long link quadrilateral, i.e. to the control strut, at the hinge is guided rotatably by a furtherfork on the outer end of the control strut; and if the latter by its top edge, or by the bottom of its profile, or by indentations, forms a stop lying in front of the line of dead centre for the swing of the short arm of the peripheral canopy-spoke.

According to a further advantageous refinement, the umbrella may be partcularly compactly folded together if the inner canopy strut exhibits a profile of U section opening outwards towards the canopy cover, for receiving the supporting strut in the shortened state of the umbrella, and, preferably the supporting strut as well as the control strut consist of hollow U profiles arranged the other way round.

Another operationally favourabie refinement may be achieved if the scissor-hinge between the inner canopy strut and the supporting strut is arranged off-centre from the latter and the latter at its end connected to the short arm of the peripheral canopy-spoke is provided with a knee bent towards the controls trut.

Preferably, the inner canopy spoke has, in the direction from the crown towards its scissors handle, a steadily thickening profile.

A particularly stress-resistant hinge connection of the scissors drive may be achieved, if the inner canopy spoke engages by a bearing tongue on the scissors hinge with a forked tongue arranged on the supporting strut and the formed tongue is flanked by the fork.

In this case a simplification in production technique may be achieved if the form is formed from two flank pieces.

The invention will now be explained in greater detail byway of example, with reference to the accompanying drawings, in which: Figure 1 shows a umbrella with a frame in accordance with the invention in the folded-together state; Figure 2 is a detail on an enlarged scale of the scissors-hinge region of the canopy linkage; Figure 3 shows half of the umbrella in the stretched state, seen from the side; Figure 4 shows, the umbrella in the same view but with the canopy turned inside out upwards parabolically by a gust of wind; Figure 5 is a detail on an enlarged scale of the region of the outer short link of the link quadrilateral of the canopy struts, considered from above; Figure 6 shows the same outer region of the link quadrilateral in an enlarged side elevation;; Figure 7 shows half of the umbrella seen from the side in the intermediate phase between the state turned inside out upwards and the state relieved of stress, being turned back downwards; and, Figure 8 is an enlarged detail of another variant upon the scissors-hinge region.

The umbrella has a stick 1 which preferably consists of a number of parts which can be telescoped into one another. At the bottom end of the stick 1 is fastened a handle, which is not shown, and at the top end of the stick 1 a crown 2. A slider3 can be shifted up and down the stick 1 and, at least in the uppermost end position with the umbrella canopy opened as may be seen from Figures 3 and 4, can be fixed by a catch 5 provided with a pushbutton 4. By means of the slider 3 the canopy of the umbrella, of which for the sake of clarity merely one half is illustrated, can be opened by shifting the sliders towards the crown 2 and vice versa.

The canopy of the umbrella consists of a number of forks hinged pivotally in the shape of a star onto the crown 2 and onto the slider 3 and a canopy cover 6 carried by them. The forks of which merely one is illustrated, exhibit respectively an inner canopy strut 7 hinged onto the crown 2 and a supporting strut 8 hinged into the slider 3. The latter and the inner canopy strut 7 are pivoted together, crossing over one another by a scissors-hinge 9 and accordingly form a scissors lever drive which by means of the slider 3 can be folded together (Figure 1) and spread apart (Figures 3 and 4). The inner canopy strut 7 and the supporting strut 8 consist of rods having a Uprofile, the open troughs of which face the canopy cover 6. The scissors-hinge 9 lies in a fork 7a on the inner canopy spoke 7, which has been produced by stamping out the bottom of the U-profile and supports the supporting strut 8, guiding it laterally.

The fork 7a extends along the whole length of a short scissors handle 7b of the inner canopy strut 7 and is in practice identical with this short scissors handle 7b, whilst the part of the supporting strut 8 extending beyond the scissors-hinge 9 forms a long scissors arm 8a. The supporting strut 8 is journalled in the fork 7a in a tongue 8c shaped at one side of its top edge 8b, that is, offcentre and at the end of its scissors arm 8a runs out into a knee 8d pointing downwards.

If the scissors handle 7b of the inner canopy strut 7 is made as a knee and the U-profile of this canopy strut has a wider trough than the profile of the supporting strut 8, the scissors arm 8a of the latter can be in the folded-together position of the umbrella in accordance with Figure 1, swing into the inner canopy strut 7 like a box into its lid and the remaining parts of the fork lie flush against the inner canopy strut 7. A folding of the folded-together umbrella which is flush with the stick and narrow in cross-section can accordingly be achieved.

Furthermore the inner canopy strut 7 may as illustrated be so constituted that the longitudinal flanges 7c at the sides of its profile, extending from the crown 3 towards the scissors handle 7b, become steadily wider or respectively taper out. The inner canopy strut 7 thereby has over the length of it an unequal moment of inertia, with the effect that the moment of resistance too remains designed to correspond with its loading or respectively the stress acting upon it remains correspondingly equal to the unequal cross-section.

The previously described scissors lever drive of the respective forks actuates a link parallelogram or at least a link quadrilateral Pwhich in turn folds a peripheral canopy-spoke 10 to rest against the link quadrilateral P in the folded-together position in accordance with Figure 1, or folds it away from the link quadrilateral P into the opened position of the umbrella canopy in accordance with Figures 3 and 4.

The peripheral canopy-spoke 10 which preferably consists of wire which can bend in all directions, forms in combination with the canopy cover 6 resting against it, the parabolic outer contour of the umbrella canopy. The canopy cover 6 is stitched at the ends of the peripheral canopy-spokes 10 onto tips 10b, is fastened by a stitched connection 6a onto a short arm 1 ova of the peripheral canopy spokes 10, is connected by means of a thread or a loop 6b to the inner canopy strut 7 and at the centre of the canopy is fixed between the crown 2 and a cap 20 mounted on it. Between the crown 2 and the stitched connection 6a the canopy cover6 stretches across the scissors lever drive 7,8 and the link quadrilateral P unsupported in a straight run with the canopy opened. The thread or the loop 6b is adapted in length to this run.

The long links of the link parallelogram or link quadrilateral Pare formed by the scissors arm 8a and by a control strut 11, whilst the short lengths are provided by the scissors handle 7b of the inner canopy strut 7 and the short arm 1 0a of the peripheral canopy-spoke 10. In this case the scissors arm 8a is the upper long link, the control strut 11 is the lower long link lying below it, the scissors handle 7b is the inner short link and the short arm 10a is the outer short link of the link quadrilateral P.

The scissors handle 7b is connected by a hinge 12 to the short arm 1 0a, and the latter is connected to the control strut 11 by a hinge 13 and the control strut 11 again is connected to the forked scissors handle 7b by a hinge 14.

At the hinge 14 the control strut 11 is journalled in the fork 7a of the scissors handle 7b so that it is guided laterally, whilst at the other end, by means of a fork 1 1a, it embraces the short arm 10a of the peripheral canopy spoke 10 at the hinge 13 so that it is guided laterally. The short arm 10a of the peripheral canopy-spoke 10 in turn embraces the scissors arm 8a at its knee 8d by means of a fork 10a' so that it is guided laterally, whilst the scissors arm 8a itself has the same lateral guidance at the scissors hinge 9 in the fork 7a of the scissors handle 7b. These laterally guided hinge connections enable an accurate congruent alignment of the scissors lever drive 7,8 of the link parallelogram P and of the peripheral canopy-spoke 10 in all phases of movement and positions.The control strut 11 preferably consists also of a rod having a U-profile the open trough of which faces the scissors arm 8a arranged above it.

The previously described arrangement and construction is as a whole such that upon shifting of the slider 3 in the opening sense, out of the position in accordance with Figure 1 in the direction outwards towards the crown 2, the scissors lever drive 7,8 is spread apart. This in turn first of all opens the link parallelogram or the link quadrilateral P over the intermediate phase, say, in accordance with Figure 7, and after that closes it again as far as the locking position which may be seen from Figure 3 with the links lying against or in one another to such an extent that the hinge 14 connecting the inner canopy strut 7 at its scissors handle 7b (the short inner link) to the control strut 11 (the lower long link) is lying in the closest possible proximity with respect to the line of dead centre i.e. the diagonal D of the link parallelogram Quite near to the supporting strut 8 at its bottom edge 8e, or by swinging further clockwise rests against it with the formation of a bearing stop A' whilst the hinge 12 connecting the supporting strut 8 at its scissors arm 8a (the upper ling link) to the short arm 10a (the short outer link) approaches the top edge 11 b of the control strut 11 anticlockwise until it adopts from above with respect to the line of dead centre, i.e. the diagonal D, a distance about equal to the distance of proximity of the hinge 14, and the link parallelogram or link quadrilateral P appears as a flat-pressed triangular formation T. This formation has an obtuse angle a and forms a compact combination with integrated scissors arms 7b and 8a of the scissors lever drive 7,8. The bearing stop A' can also be achieved by the inner end of the control strut 11 resting against a bottom edge 8e of the supporting strut 8. If the hinge 14 comes to rest directly against the bottom edge 8e, the inner end of the control strut 11, with its U-profile open upwards, can also allow the bottom edge to dip a little into the trough of the profile and let the formation T, with its obtuseangled outerside defined by the arm 10a, appear still more obtuse and diminished. This compact combination of driving scissors and link parallelogram enables optimum stabilization of the canopy in its central region which is especially endangered by deformation or rupture, in particular in the case of excessive stresses and distortions originating from wind forces.

If these excessive stresses increase so much that turning of the canopy doming inside out upwards occurs, as shown in Figure 4, the outer short link embodied in the short arm 10a of the peripheral canopy spoke 10 folds through the remaining few degrees of clearance towards the top edge lib of the control ctrut 11, with the formation of a second bearing stop A" against the control strut 11, so that the link parallelogram or link quadrilateral P adopts a completely blocking position in association with the scissors lever drive, with the formation of two stabilizing bearing stops A' and A".Because of this stabilization considerable tensile forces on the middle region of the umbrella canopy, which is in danger of deformation or rupture, get deflected into the outer region of the flexible peripheral canopy spokes 10 with the final effect of considerable protection of the middle region supported by the scissors lever drive 7, 8 and the link parallelogram P.

The bearing stops A' and A" also guard against the risk of a buckling-through, or a sideways shearing out of line of, the parallelogram links and a thereby possible deformation or destruction of these parts or their hinges. Finallythisspecial mechanism further makes it possible to restore the inverted and strained canopy by pulling the slider3 down in the direction of the arrow R in Figure 7, as gently as possible into the regular doming once more. The stress movement to be covered in that case in overcoming the strain (arrow S) is, when measured at the displacement (arrow R) of the slider 3, comparatively short.

The bearing stop A" can be effected by the short arm 10a of the peripheral canopy spoke 10 coming up against the top edge 11b of the control strut 11 or against lobes, bosses or indentations 1 Ic, etc formed on it and/or against the web lid at the bottom of the U-profile of the control strut 11 (Figure 6). The line of dead centre, or the diagonal D in the link parallelogram orthe link quadrilateral P, indicated in dash-dot line in Figures 3,4 and 6 follows from the diagonal drawn between the hinges 9 and 13.The canopy cover 6 may, if the inner canopy strut 7 is open in its profiling towards the canopy cover 6, upon folding of the umbrella together, be drawn in and folded in by the threads or loops 6b in such a way between the scissors arm 8a and the inner canopy strut 7 that it finds room in the cavity in the canopy strut 7 together with the scissors arm 8a nesting into it, and thus the foldedtogether umbrella in its cross-section may be shaped into a small volume. This nesting of the scissors arm 8a inside the canopy strut 7 naturally presupposes a correspondingly thinner crosssection of the supporting strut 8 as also the possible slight mating of the control strut 11 and the scissors arm 8a in the previously described blocking position of the link parallelogram P implies at least in crosssection the same hollow profile with open troughs facing upwards, of the parts 8 and 11.

Instead of a U-shaped profiling of the crosssection the parts of the canopy linkage may also have other known hollow profilings and/or as is likewise known, may consist of round or flat struts arranged in parallel side by side.

The bearing connection between the inner canopy spoke 7 and the supporting strut 8 at the scissors hinge 9 may be designed to be particularly resistant to loading if the inner canopy strut 7 engages at the scissors hinge 9 also in a forked tongue 8c' on the supporting strut 8. This is in turn flanked on both sides by the fork 7a as may be seen from Figure 8, so that the two parts 7 and 8 have a double hinging and guidance against one another. The fork 7a may be a separate part fixed to the inner canopy spoke 7 or else consist of separate and appropriately fixed flank parts 7a', 7a'. The intermediate arranged fork tongue 8c' may be formed on an U-shaped insert 8c" fixed within the hollow profiling of the supporting strut 8, for example by lugs 80. The flank parts 7a', 7a' may be fixed to the inner canopy strut 7 by a rivet 81. If the inner canopy strut 7 furthermore is hinged by means of tongues 7d, 7d to the scissors hinge 9 a threefold stabilized hinging and guidance ofthe scissors arrangement may be achieved. The tongues 7d, 7d are-formed by the forked or upset end of the inner canopy strut 7 and may be movable arranged within the both forked tongues 8c', 8c' or more outside, between these tongues and the flank parts 7a', 7a'.

Claims (10)

1. A shortenable umbrella frame having a stick with a fixed crown, a slider and a plurality of inner canopy struts each hinged at its inner end to the crown each innercanopy strut crossing, and being connected by a scissors hingeto, a respective supporting strut which is hinged at its inner end to the siider, a scissors handle portion ofeach inner canopy strut extending outwards beyond the scissors hinge and being hinged to the inner end of a respective control strut which extends outwards beneath the supporting strut, and a plurality of peripheral canopy spokes each of which is hinged to the outer end of a respective control strut and has, inwardly of this latter hinge, a short arm hinged to the outer end of the supporting strut, whereby the scissors handle and short arm form short links, and the control strut and the portion of the supporting strut above the control strut form long links, of a link quadrilateral; characterized in that the hinge connecting each inner canopy strut to the respective control strut lies in the opened position of the frame, adjacent to the diagonal through the scissors hinge of the link quadrilateral and lies adjacent to the bottom edge of the supporting strut so that the link quadrilateral appears as a triangle with an obtuse angle adjacent to the hinge connecting the supporting strut and the short arm, and the hinge connecting the supporting strut to the short arm adopts from above substantially the same distance from the diagonal as that connecting the inner canopy strut to the control strut adopts from below the diagonal.

2. A frame according to claim 1, characterized in that the scissors handle consists of a fork which supports and guides the scissors-hinge; the supporting strut and its hinge thereto; that the short arm at one end, by means of a further fork, guides the hinging of the upper long link of the link quadrilateral, and, at the other end, in its hinged connection to the lower long link of the link quadrilateral is guided by a further form on the outer end of the control strut; and that the control strut forms a stop for the swinging of the short arm.

3. A frame according to claim 2, in which each inner canopy spoke engages via a bearing tongue at its scissors hinge with a forked tongue arranged on the respective supporting strut; and the forked tongue is flanked by the fork.

4. A frame according to claim 2 or claim 3, in which the fork is formed from two flank pieces.

5. A frame according to any one of the preceding claims, in which the inner canopy strut has a hollow profile of U-section, facing outwards, for receiving the supporting strut in the closed state.

6. A frame according to claim 5, in which the supporting strut and the control strut also have hollow profiles of U-section.

7. A frame according to any one of the preceding claims, in which the scissors-hinge is arranged offcentre from the respective supporting strut, the end of which connected to the short arm is provided with a knee bent towards the control strut.

8. A frame according to any one of the preceding claims, in which the inner canopy spoke has, in the direction from the crown towards its scissors handle, a steadily thickening profile.

9. A shortenable umbrella frame, substantially as described with reference to the accompanying drawings.

10. A shortenable umbrella, incorporating a frame according to any one of the preceding claims.