GB2369993A

GB2369993A - Inflatable umbrella with rim recesses to avoid skewing of the inflatable frame

Info

Publication number: GB2369993A
Application number: GB0118061A
Authority: GB
Inventors: John Neville Trickett
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-12-16
Filing date: 2001-07-25
Publication date: 2002-06-19
Also published as: GB0118061D0; GB0030798D0

Abstract

An umbrella consisting a canopy,1, with an inflatable frame,2, with recesses round the rim (fig 8, 9), to prevent skewing when the frame is inflated. Inflation means can be incorporated as part of the shaft,4, and handle,5, as either a manual pump or a disposable/rechargeable gas cartridge. When inflated, the canopy forms a cone shape, with the frame forming another cone, inverted to the canopy, to provide strength in high winds (fig 3).

Description

UMBRELLA

This invention relates to an umbrella and more particularly to an umbrella with an inflatable frame.

The term"umbrella"as used herein is intended to also cover parasols and the like and is to be construed accordingly.

The use of devices such as umbrellas and parasols to protect one's body, and particularly one's head and upper torso, from the elements is widespread.

A fundamental problem associated with this type of commonly known device is the safety aspect. Specifically, upon opening the device, often a person standing in close proximity to the user may be in danger of, or actually be, hit or jabbed by the pointed end of one or more of the struts of the frame holding the canopy.

Another drawback associated with these devices is that, during harsh weather conditions, the structural stability of the frame holding the canopy is often found to be lacking, and this leads to the canopy being turned inside out and consequently damage to the frame.

The present invention seeks to overcome these problems.

According to one aspect of the present invention, there is provided an umbrella comprising a canopy, an inflatable frame attached to the canopy, inflation and deflation means, a shaft attached to the inflatable frame and to the canopy, and a handle or grip on the shaft.

Preferably, the inflatable frame comprises a central chamber and a plurality of struts in fluid communication with the central chamber. In this case, the inflatable frame may further comprise an inflatable rim in fluid communication with one or more of the struts. Conveniently, the inflatable rim includes a plurality of recesses.

The recesses may be formed in outwardly facing portions of the rim opposite the struts. However, the recesses may alternatively be in the form of a plurality of circumferentially spaced apart constrictions.

Preferably, when the frame is inflated, the canopy forms a cone shape.

Furthermore, when the frame is inflated, the frame may define a cone shape. In the case when the canopy forms a cone shape and the frame defines a cone shape, the cone shape defined by the frame is inverted relative to the cone shape of the canopy.

Preferably, the inflation and deflation means comprises at least one valve by which the frame can be inflated and deflated. In this case, the at least one valve may be integrally formed as part of the attachment between the shaft and the inflatable frame. In this case, the inflation and deflation means may further comprise a

manually operated mechanical pump incorporated as part of the shaft and handle, the outlet of the pump being in fluid communication with the inflatable frame via the said at least one valve.

Alternatively, the inflation and deflation means may comprise a manually activated compressed gas reservoir incorporated as part of the shaft and handle, the outlet of the gas reservoir being in fluid communication with the inflatable frame via the said at least one valve. In this case, the said compressed gas reservoir may be a rechargeable compressed gas reservoir, or may be a disposably replaceable compressed gas cartridge.

The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a top perspective view of one embodiment of an umbrella, in accordance with the present invention; Figure 2 is a perspective view of a frame structure of the umbrella shown in Figure 1; Figure 3 is a sectional view showing the inflated position of the frame and canopy in relation to the shaft;

Figures 4a and 4b are schematic side views depicting the inherent shortening of a strut upon inflation ; Figures 5a and 5b are schematic cross-sectional views depicting the inherent shortening of the strut upon inflation; Figure 6 is a schematic view diagrammatically showing typical forces generated at the junction between strut and rim of an inflatable umbrella; Figure 7a is an enlarged schematic view showing a portion of the frame at a junction between rim and strut; Figure 7b is an enlarged schematic view similar to Figure 7a showing movement of the portion of the frame between an uninflated condition and an inflated condition; and Figures 8a and 8b show modifications to the rim of the umbrella.

Referring to the drawings, the umbrella shown therein comprises a canopy 1, an inflatable frame 2 attached to the canopy 1, inflation and deflation means 3, a shaft 4 attached to the inflatable frame 2, and a handle or grip 5 on the shaft 4.

The inflatable frame 2 typically comprises a central inflatable chamber 6 which is slidably received on the shaft 4 and which can be releasably fixed or held in position on and relative to the shaft 4, a plurality of inflatable struts 7 in fluid communication with and radially extending from the central chamber 6, and an inflatable rim 8 in fluid communication with one or more of the struts 7.

A problem associated with inflatable umbrellas occurs when attempting to inflate a frame that utilises radially extending inflatable struts and an inflatable rim interconnecting and in fluid communication with the struts. Upon inflation, there occurs an inherent fore-shortening of the struts, as shown in Figures 4a, 4b, 5a and 5b. If there is no compensating reduction at the rim, opposing forces, diagrammatically shown in Figure 6, are induced in the vicinity of the junction between the struts and the rim. These forces are generally directed towards one another and attempt to forcibly decrease the circumference of the rim. This leads to bulging of the rim and deformation or squewing of the frame.

The rim 8 is therefore shaped to prevent the frame 2 from distorting or squewing due to the inherent fore-shortening of the struts 7 which occurs during inflation. As can best be seen in Figure 7a, an outwardly facing portion of the rim 8 at the junction of the rim 8 and each strut 7 is formed with a tuck or recess 9. As schematically shown in Figure 7b, on inflation (represented in Figure 7b by dotted lines), the tuck or recess 9 is drawn radially inwards due to the forces generated by

the inherent fore-shortening of the struts 7. Since the material from which the frame 2 is formed does not stretch or substantially stretch under normal use, the uninflated distance Al-A2 along the outer circumference of the rim 8 has to equal the inflated distance ai-a2. Consequently, the diameter of the rim 8 is reduced in proportion to the fore-shortening of the struts 7, thereby preventing or substantially preventing any squewing and/or bulging.

The canopy 1 typically comprises a single sheet which is attached to and extends from the shaft 4 and which is also attached at its circumference to the inflatable rim 8. On inflation, the canopy 1 is pulled into tension, forming a conical shape, by the frame 2. The central chamber 6 is held at a position on the shaft 4 which is offset towards the handle or grip 5 from the plane in which the edge of the cone-shaped or tensioned canopy 1 lies. This positioning of the central chamber 6 forces, on inflation, the remainder of the frame 2 to be pulled upwards into tension by the canopy 1. The frame 2 thus itself, on inflation, defines a cone shape which is inverted relative to the cone defined by the canopy 1.

Since, on inflation, both the canopy 1 and frame 2 are in tension, a reduced air pressure can be utilised in the frame 2 in comparison to a frame that extends perpendicularly or substantially perpendicularly to the shaft 4. This arrangement ensures that attempts to deform the umbrella by adverse wind conditions are resisted by the fact that the circumference at the rim 8 would have to be reduced by

considerably more than the tucks or recesses 9 permit to allow the struts 7 to pivot further upwards about their centres or point of connection to the central chamber 6.

The inflation and deflation means comprises a valve, such as a releasable nonreturn valve, integrally formed as part of the attachment between the shaft 4 and the frame 2, and a manually operated mechanical pump. The pump is incorporated as part of the shaft 4 and the handle or grip 5, and is in fluid communication with the frame 2 via the said valve.

Alternatively, in a modification (not shown), the inflation and deflation means comprises a valve, such as a releasable non-return valve, integrally formed as part of the attachment between the shaft 4 and the frame 2, and a compressed gas reservoir which is situated in the shaft 4 and/or handle or grip 5 and which is in fluid communication with the frame 2 via the said valve. Release of the compressed gas is manually effected typically via a button disposed on the handle or grip 5. In this case, the compressed gas reservoir may be rechargeable, or may be in the form of a disposable and replaceable compressed gas cartridge.

In modifications to the shaping of the rim 8 to compensate for the inherent fore-shortening of the struts 7 on inflation, the recesses 9 in the rim 8 could instead take the form of a plurality of circumferentially spaced apart constrictions. As shown in Figures 8a and 8b, the number of constrictions per unit length can vary and can

cause the rim 8 to a have different profile. In Figure 8a, the constrictions are spaced apart around the rim 8 and the portion of the rim 8 intermediate the constrictions is of generally uniform cross-section. In Figure 8b, the rim 8 in the circumferential direction has a generally sinusoidal cross-section.

It is therefore possible to provide an umbrella with an inflatable frame which is easy to deploy, structurally stable in adverse weather conditions, relatively nonhazardous to passers by during deployment, and which takes on a desired shape upon inflation.

The umbrella described above is given by way of example only and various modifications will be apparent to persons skilled in the art without departing from the scope of the invention.

Claims

1. An umbrella comprising a canopy, an inflatable frame attached to the canopy, inflation and deflation means, a shaft attached to the inflatable frame and to the canopy, and a handle or grip on the shaft.

2. An umbrella as claimed in claim 1, wherein the inflatable frame comprises a central chamber and a plurality of struts in fluid communication with the central chamber.

3. An umbrella as claimed in claim 2, wherein the inflatable frame further comprises an inflatable rim in fluid communication with one or more of the struts.

4. An umbrella as claimed in claim 3, wherein the inflatable rim includes a plurality of recesses.

5. An umbrella as claimed in claim 4, wherein the recesses are formed in outwardly facing portions of the rim opposite the struts.

6. An umbrella as claimed in claim 4, wherein the recesses are in the form of a plurality of circumferentially spaced apart constrictions.

7. An umbrella according to any one of the preceding claims, wherein, when the frame is inflated, the canopy forms a cone shape.

8. An umbrella as claimed in any one of the preceding claims, wherein, when the frame is inflated, the frame defines a cone shape.

9. An umbrella as claimed in claim 8 when dependent on claim 7, wherein the cone shape defined by the frame is inverted relative to the cone shape of the canopy.

10. An umbrella according to any one of the preceding claims, wherein the inflation and deflation means comprises at least one valve by which the frame can be inflated and deflated.

11. An umbrella as claimed in claim 10, wherein the at least one valve is integrally formed as part of the attachment between the shaft and the inflatable frame.

12. An umbrella as claimed in claim 11, wherein the inflation and deflation means further comprises a manually operated mechanical pump incorporated as part of the shaft and handle, the outlet of the pump being in fluid communication with the inflatable frame via the said at least one valve.

13. An umbrella as claimed in claim 11, wherein the inflation and deflation means

further comprises a manually activated compressed gas reservoir incorporated as part of the shaft and handle, the outlet of the gas reservoir being in fluid communication with the inflatable frame via the said at least one valve.

14. An umbrella as claimed in claim 13, wherein the said compressed gas reservoir is a rechargeable compressed gas reservoir.

15. An umbrella as claimed in claim 13, wherein said compressed gas reservoir a disposably replaceable compressed gas cartridge.

16. An umbrella substantially as hereinbefore described with reference to Figures 1 to 3,7a and 7b, Figure 8a, and Figure 8b of the accompanying drawings.