GB2235375A

GB2235375A - Shortenable umbrella frame

Info

Publication number: GB2235375A
Application number: GB8922656A
Authority: GB
Inventors: Joachim Seidel; Klaus Stiller
Original assignee: KORTENBACH VERWALTUNG
Current assignee: KORTENBACH VERWALTUNG
Priority date: 1989-08-16
Filing date: 1989-10-09
Publication date: 1991-03-06
Anticipated expiration: 2009-10-09
Also published as: GB2235375B; GB8922656D0; DE3927029C1

Abstract

A shortenable umbrella having triply contractible canopy ribs (D1, D2, D3) a telescopic stick (1) and a slider (2) displaceable thereon to which are pivoted struts (3) which pivotally support the inner canopy rib pans (D1). There are two parallelograms linkages (I, II) associated with each set of canopy ribs. A control rod (10) of the first parallelogram linkage is essentially rectilinear and resiliently flexible but is arranged with joints (9, 11) in turned down ends of the control rod in such a way that at the start of the closing movement of the umbrella canopy the control rod bows inwards towards, and into abutment with, the canopy rod and consequently forms an enlarged lever arm with respect to the fulcrum of the control link (8) with the inner rib part (D1). <IMAGE>

Description

50/3867/01 1

DESCRIPTION

SHORTENABLE UMBRELLA FRAME The invention concerns a shortenable umbrella frame of the kind, hereinafter referred to as the kind describedy the frame having triply contractible canopy ribs; a telescopic stick and a slider displaceable thereon; struts each pivotally connected at one end to the slider and at the other end to a respective inner canopy rib part, which is pivotally connected at its inner end to a crown at the upper end of the stick; substantially rectilinear and resiliently flexible control rods each running substantilly parallel to a respective inner rib part, the control rod forming, with theadjacent section of the respective inner rib part, the outer end of the respective strut and a lever arm formed by the inner end of a respective control link associated with a respective middle canopy rib part, a first lever parallelogram linkage, to which there is pivotally connected a respective second parallelogram linkage, the long links of which are formed in each case by a middle rib part and its control link, and the short links of which are formed in each case by the outer end of the respective inner rib part, which end is joined to the respective middle rib part and its control link, and a lever arm formed by the inner end of an outer canopy rib part, which is pivotally connected via its lever arm to the outer ends of the respective middle rib part and of its control link.

Umbrellas with frames of this, or of a similar, kind are already known and are described, for example, in US-A-4030514 or in JP-C-60-3482. The canopy ribbing of such umbrellas is designed extremely flat,, can be opened and closed in a force-controlled fashion with simultaneous automatic 50/3867/01 2 is folding in of the canopy covering, and can also be collapsed and shortened to a shape occupying a low volume. The extremely flat and inherently very closely fitting design of the canopy ribbing necessarily also results, however, in very unfavourable lever ratios in the parallelogram linkages. This has the consequence that, when put up, the umbrella canopyr which is subjected to a relatively high peripheral tensioning thrust, can be drawn tight only with a large expenditure of force. Finally, this insensitive operating requirement necessarily also entailsf in its turn, that parts of the umbrella canopy are also often damaged or completely broken.

It is the object of the invention to improve an umbrella frame of the kind described in such a way that, in use, it is free-running during opening and closing, and thus operationally reliable, and that there is no danger that in this process parts of the umbrella canopy are deformed or broken.

According to the invention, in a frame of the kind described, the pivotal connections between the ends of each control rod and the respective strut and control link are offset to the side of the centre line of the control rod away from the canopy ribst so that at the start of the closing movement of the frame the control rod contracts, forming an arc, in use,, against the peripheral thrust torque of the tensioned canopy covering and bows inwards towards, and into abutment within, a hollow profile of the respective inner canopy rib part and consequently forms an enlarged lever arm with respect to the fulcrum of the control link and inner rib part.

In this way, an umbrella with such a frame is an improvement over previous umbrellas, in its operational reliability, stability and ease of operation. The umbrella canopy can be opened as r 50/3867/01 3 smoothly as it can be closed. During closure of the umbrella canopy, the slider can be pulled down without special expenditure of force despite the high peripheral thrust torque of the tensioned canopy covering bearing upon the umbrella frame. This results from the fact that in the first phrase of the closing movement the resiliently flexible control rods are firstly bowed into the hollow profiles of the inner rib parts as a consequence of the specified desired bending directiony and thereby contract from the essentially rectilinear starting position, with the consequence that they thereby ultimately create enlarged lever arms with respect to the fulcrum joints of the control links, doing so for as long as the high pressure-loading torque of the tensioned canopy covering is maintained. Owing to the improvded lever ratio thus effected, the canopy ribbing can be collapsed smoothlyl without special expenditure of force and without snags until the high peripheral tensioning thrust practically vanishes or is completely relieved. Subsequently, the canopy can be equally smoothly collapsed entirely into the closed final position, the control rods being once again substantially straightened. Finally, owing to the smoothness achieved in the closing process of the umbrella canopy, the danger present with the known umbrellas of this type of deformation or breakage of parts of the umbrella canopy is also avoided.

An especially advantageous construction results if, in the startingr i.e. open, position of the frame, each control rod is bowed slightly towards the respective inner rib part.

The invention is described by way of example and in more detail with reference to the accompanying drawings, in which:

Figure 1 shows part of an umbrella frame constructed according to the invention, having three 0 50/3867/01 4 canopy rib parts which may be folded against one another and are shown in the closed state; Figure 2 shows the same part of the frame in the open state; Figure 3 shows the same part in the half opened state and, dot-dashed, in two further intermediate collapsed positions; Figure 4 shows the detail of the umbrella canopy ribbing according to the section A and B of the Figure 3, to an enlarged scale; and, Figure 5 shows the part frame with half opened canopy.

The illustrated contractible collapsible umbrella frame has having three canopy rib parts Dl, D2 and D3. which may be folded one against another and, starting from an umbrella crown 4F continue uninterrupted as far as the outer ends of the canopy rib parts D3. The umbrella has a telescopic stick -1. which has_ at least two telescopic parts and on which there is a slider 2 which is movable up and down.

Swivellably pivoted on the latter at joints 31 are struts 3. The struts 3 support, at pivoted joints 6, the inner canopy rib parts Dl. which are pivoted to the umbrella crown 4 at joints 5.

For the sake of clear representation, the drawing shows in each case only part of the umbrella with only one canopy rib and its associated linkage.

Similarly ribs are arranged radially around the umbrella crown 4. Connected to the inner rib part Dl is a middle canopy rib part D2, and pivoted in turn to the latter is an outer canopy rib part D3. The inner canopy rib part Dl is swivellably joined with its outer end via a joint 7 to a short lever arm 8a of a control link 8 associated with the middle canopy rib part D2. The short lever arm 8a can be constructed as a hinge S having an upwardly open U-profile, which embraces the canopy rib part Dl.

50/3867/01 1 The lever arm 8a is swivellably joined via a joint 9 to a control rod 10 which, for its part, engages via a joint 11 with the strut 3. The control rod 10 runs approximately parallel to the section D11 of the inner canopy rib part Dl, which section extends between the joints 6 and 7. In this way, the section D11 and the control rod 10 form the long linksr and the short lever arm 8a and the section 3a of the strut, which section is located between the joints 6 and llr form the short links of a first parallelogram linkage I.

The control rod 10 is essentially rectilinear and flexually elastic. The joint eyelets 10a and 10b on the two ends of the control rod lOr which are rotatably seated on the joints 9 and 11 of the control link 8 and of the strut 3F are integrally formed on parts of the control rod 1OF which are turned downwards with respect to the straight line of this rod and point away from the inner rib part Dl.

Consequentlyr the effect is that the control rod 10 always has the predetermined tendency to buckle in an arc in the direction of the rib part Dl? which has a downwardly facing hollow profile, as soon as it comes under compression loading. This is the case if upon closure of the umbrella canopy the slider 2 is pulled downwards, and a torque MR (Figure 4) should arise at the joint 9 due to the control rod 10 and the control link 8. As a consequence of the high peripheral tensioning thrust P of the tensioned canopy covering 18, this is counteracted at the small lever arm 8a of the control link 8 by the torque MC, so that, because of the insufficiently large lever arm alf the control rod 10 is at first not yet able to cause the control link 8 to execute a collapsing movement in the clockwise direction. Nevertheless, the increasing curvature of the control rod 10 already facilitates, as a consequence of its contraction thereby effected, 50/3867/01 1 J 6 the pulling down of the slider 2, and the downward collapse associated therewith of the uncollapsed canopy rod, which is still stretched. This operation already runs smoothly and without snags, despite the existing high peripheral tensioning thrust P of the canopy covering 18.

As the slider 2 is pulled further down, the control" rod 10 finally reaches its maximum flexurer in that it completely bends as far as the base of the hollow profile of the rib part Dlr abuts a stop Z and thus achieves a maximum contraction in its length. In association therewith, the distance between the pivot points 9 and 11 of the control rod 10 (see dot-dashed chord length of 10 in Figure 4) is shortened, as thus also the distance between the pivot point 11 and the fulcrum 7 of the control link 8. The result of the maximum flexure of the control rod 10 is also that the lever arm aly from the dot-dashed_ enlargement of Figure 4, is enlarged in accordance with section B from Figure 3r with respect to the fulcrum 7 of the control link 8r starting from the stop Z. The lever arm a" is substantially larger than the lever arm alf as results from the sections A and B of the positions of the opened umbrella canopy (unbroken lines of Figure 3 and 4). or of the already partially collapsed but still inherently stretched canopy ribbing (lines drawn in with dots and dashes in Figures 3 and 4).

The state P 0 or the cancellation of the thrust torque P from the peripheral tensioning of the canopy covering 18 coincides simultaneously or approximately simultaneously with the pulling down of the slider 2 (torque MR), the maximum flexure of the control rod 10 and the achievement of the enlarged lever arm am as well as of the swung downr but still inherently stretched position of the canopy kinematics according to the slider position M of 1 50/3867/01 7 Figure 3. Subsequently hereafterr as a consequence of the enlarged lever arm am, as the slider 2 continues to be pulled down, the control rod 10 brings the middle parallelogram linkage II to the collapsed position N according to Figure 3r the control rod 10 in turn being increasingly resiliently deformed into its essentially rectilinear starting position, which it then finally reaches still during the last closing phase of the umbrella canopy. In this wayr despite the high thrust torque P of the tensioned canopy covering 18, and despite the unfavourable lever ratios in the canopy kinematics, all phases of the closing movement of the umbrella canopy run smoothly.

The middle canopy ribbing of the parallelogram II can have a one-piece canopy rib part D2 or a canopy rib part D2 consisting of two parts D21 and D2N. If the latter is in two parts, the parts D21 and D21 are swivellably joined by a slider element 13, which is guided displaceably on the control link 8. The control link 8 is swivellably joined via a joint 14 to the outer canopy rib part D3. Part D21 is swivellably joined via a joint 15 to the inner canopy rib part D1, and while part D2" engages rotatably on the outside via a joint 16 with the short lever arm D31 of the outer canopy rib part D3. Accordingly, with its two parts D21 and D2 the middle canopy rib apart D2 forms in conjunction with the control link 8 the long links, and the short lever arm D31 of the outer canopy rod D3 forms in conjuction with the short lever arm Dla between the links 7 and 14 the short links of the second lever parallelogram linkage II.

The previously described three-part canopy 35 ribbing can be swung up by displacing the slider 2 on the telescopic stem 1 into the opened position of the umbrella canopy (Figure 3), and contracted into the 50/3867/01 1 8 collapsed position (Figure 1). In this connectiony the canopy rib parts D1 and D2 swing upwards, forming a fold bend K' open towards the umbrella crown 4. the canopy covering 18 which, for example, is attached in this fold bend K' by means of a string 17 at the canopy rib part D1 or in the hollow joint 150, preferably also being pulled in and folded in in the same fold bend V. By contrastr upon collapse of the umbrella canopyp the outer canopy rib parts D3 swing away from the crown 4. forming a second fold bend K against the control link 8, so that when folded up they point with their ends D31 to the umbrella handle (not shown).

In the folded-up position of the umbrellay the canopy rib parts D1 and D2 can fit into one anothery so that the folded-up bundle of the canopy ribbing with the canopy covering 18 becomes thin and slim in its cross-section. In the opened position of the canopy, the.slider 2 can be locked on the telescopic stem 1 by means of an arresting latch R. The chord of the flexed control rod 10 is designated by bs, and the dead-centre line of this rod with respect to the small lever arm 8a is designated by DC.

J I- 50/3867/01 1 1 9

Claims

1. A shortenable umbrella frame having triply contractible canopy ribs; a telescopic stick and a slider displaceable thereon; struts each pivotally connected at one end to the slider and at the other end to a respective inner canopy rib part, which is pivotally connected at its inner end to a crown at the upper end of the stickI substantially rectilinear and resiliently flexible control rods each running substantilly parallel to a respective inner rib part, the control rod forming, with the adjacent section of the respective inner rib part, the outer end of the respective strut and a lever arm formed by the inner end of a respective control link associated with a respective middle canopy rib part, a first lever parallelogram linkage, to which there is pivotally connected a respective second parallelogram linkage, the long links of which-are formed in each case by a middle rib part and its control link, and the short links of which are formed in each case by the outer end of the respective inner rib part, which end is joined to the 'respective middle rib part and its control link, and a lever arm formed by the inner end of an outer canopy rib part, which is pivotally connected via its lever arm to the outer ends of the respective middle rib part and of its control link; wherein pivotal connections between the ends of each control rod and the respective strut and control link are offset to the side of the centre line of the control rod away from the canopy ribsy so that at the start of the closing movement of the frame the control rod contracts, forming an arcy in use, against the peripheral thrust torque of the tensioned canopy covering and bows inwards towardsi, and into abutment withinr a hollow profile of the respective inner rib part and consequently forms an enlarged bu/.5t$0 11 ViL 1, lever arm with respect to the fulcrum of the control link and inner rib part.

2. A frame according to claim 1, in which, when the frame is opent each control rod is bowed slightly in the direction towards the respective inner rib part.

3. An umbrella framer substantially as described 10 with reference to the accompanying drawings.

4. A shortenable umbrella having a canopy covering carried by a frame according to any one of the preceding claims.

is Published 1991 at Ilie Patent Offlce.St2te: House. 66/71 HigbHolborn. London WCIR47P. Further copies Tnay be obtained from Sales Branch. Unit 6. Nine Mile Point Cwmrelinfach. Cross Keys. Newport. NPI 7HZ. Printed by Multiplex techniques ltd. St Maiy Cray. Kent.