GB2273246A

GB2273246A - Trampoline

Info

Publication number: GB2273246A
Application number: GB9225909A
Authority: GB
Inventors: Paul Thomas Ryan; David John Inwood
Original assignee: INWOOD RYAN Ltd
Current assignee: INWOOD RYAN Ltd
Priority date: 1992-12-11
Filing date: 1992-12-11
Publication date: 1994-06-15
Anticipated expiration: 2012-12-11
Also published as: GB9225909D0; GB2273246B

Abstract

A trampoline has a bouncing surface 2 attached around its periphery to an inflatable tube 1 which tensions the bouncing surface 2 such that downward displacement of the bouncing surface reduces the volume of the inflatable tube and thereby increases its internal pressure. Restraining means, in the form of an inflatable volume (9 fig. 10) a frame 4 or several vertical spaced frames (fig. 4), provide a restraining force which acts on the inflatable tube 1 to maintain its shape and the tension in the bouncing surface 2 by resisting the tendency of regions of the tube to move towards one another. The tube may be annular, square or rectangular. Lower points of the tube may be interconnected by a rope 6 or similar to balance the forces on the tube from tension in the bouncing surface. <IMAGE>

Description

Title: Trampolines Field of the Invention This invention relates to trampolines, and in particular those known as "play trampolines" intended for use by young children.

Backqround to the Invention Such trampolines are in common domestic and outdoor use for the entertainment of young children, typically from the age of about 18 months to about 5 or 6 years old.

They consist typically of a metal frame (either rectangular or circular) about lm across, attached to the inside of which is a bouncing surface that is connected to the frame by elasticated ropes or springs.

There are a number of problems inherent in the construction of these products, relating to safety and ease of use. It is believed that several thousand accidents in the UK alone are caused each year through the use of trampolines. These are caused by the user: * landing on the hard metal frame around the bouncing area * missing the edge of the bouncing surface, landing between it and the metal frame and becoming trapped * bouncing near the edge of the trampoline and causing it to over balance * missing the trampoline altogether and landing on the ground. This is a problem inherent with the use of trampolines that no known design can overcome.

Existing designs are also difficult to use, because they must first be assembled in such a way as to get the tension in the bouncing surface correct.

Solutions to the above safety problems have been attempted through the use of resilient mats covering the metal frame and filling the gap between the bouncing surface and the frame. However, they add significantly to the cost and provide only limited protection.

The present invention seeks to avoid or mitigate most of the above mentioned problems.

The Invention According to the invention a trampoline comprises a bouncing surface spanning spaced regions of inflatable means which, on inflation, tensions the bouncing surface such that downward displacement of the bouncing surface reduces the volume of the inflatable means and thereby increases the pressure in the inflatable means, and restraining means which are operative, when the bouncing surface is tensioned on inflation of the inflatable means, to provide a restraining force which acts on the inflatable means to resist the tendency for the inflatable means to move in a manner which would result in a reduction of tension in the bouncing surface.

Generally, the restraining means provide a restraining force which acts on the inflatable means to resist the tendency for the regions of the inflatable means to move towards one another (which, if it occurred, would reduce the tension in the bouncing surface). However, the restraining may also resist the tendency for the regions of the inflatable means to roll or twist.

The provision of the restraining means enables a comparatively high tension in the bouncing surface to be achieved with a low pressure in the inflatable means.

The inflatable means may comprise two inflatable bodies at respective opposite sides or ends of the bouncing surface, but in preferred embodiments the inflatable means is constituted by an inflatable tube which extends around the complete periphery of the bouncing surface. The tube may in plan view be square, rectangular, annular or any convenient shape, and the tube may form a common inflatable volume, or may be divided into separate inflatable volumes.

The restraining means may be inflatable and the internal volume of the restraining means may be common with, or separate from, the internal volume of the inflatable means. In one particular embodiment, the inflatable means is a toroidal inflatable tube which surrounds a circular inflatable compartment constituting the restraining means.

Alternatively, the restraining means may comprise a frame to which the inflatable means abuts, the frame being positioned so that it is protected by the inflatable means in such a way as to prevent a user hitting the frame. To achieve this, the inflatable means preferably overlies the frame in the erected condition of the trampoline, and the inflatable means also preferably surround the frame around the outside thereof to provide lateral protection for the frame.

The frame shape will normally be dictated by the shape of the trampoline itself. Hence, if the erected and inflated trampoline is circular in plan view, the frame will normally be circular, annular or toroidal.

Another embodiment of circular trampoline has two vertically spaced rings or hoops constituting the frame.

The preferred embodiment of circular trampoline has a frame in the form of a single ring or hoop which is wholly enclosed within an inflatable generally annular or toroidal tube constituting the inflatable means. In this case, the tube may in cross-section present the shape of two lobes which adjoin at the point at which the material of the tube is attached to the ring or hoop.

The bouncing surface is preferably attached around its complete periphery to the inflatable tube forming the inflatable means, and this attachment is conveniently at or adjacent the highest point of the cross-sectional shape of the inflatable tube, a filamentary tension member, (such as a.rope) interconnecting lower points of the tube to balance the force imparted to the tube by the tension in the bouncing surface.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which Figures 1, 2 and 3 are respectively diagrammatic crosssectional, side elevation and plan views of the preferred embodiment of trampoline, Figures 4, 5 and 6 are respectively diagrammatic crosssectional, side elevation and plan views of a second embodiment of trampoline, Figures 7, 8 and 9 are respectively diagrammatic crosssectional side elevation and plan views of a third embodiment of trampoline, and Figures 10, 11 and 12 are respectively diagrammatic crosssectional side elevation and plan views of a fourth embodiment of trampoline.

Referring to Figures 1, 2 and 3, the preferred embodiment of trampoline is circular in plan view and comprises a generally toroidal inflatable tube 1 surrounding a circular bouncing surface 2 about lm in diameter. The bouncing surface 2 is made from a synthetic woven fabric material having warp and weft threads, and the complete circular outer periphery of the bouncing surface 2 is bonded to the tube 1 around a circular seam indicated at 3 in Figure 1 and 3, eliminating the possibility of any gap between the bouncing surface 2 and the tube 1. As shown in Figure 1, this circular seam 3 is disposed a little below the uppermost part of the cross-sectional shape of the tube 1.

The tube 1 is conveniently made from a composite material having a fabric outer layer and a polyvinylchloride (PVC) inner layer. Optionally, the airtight inner layer may be saparate from, be bonded to or be part of the fabric outer layer. This material is flexible, as is the material of the bouncing surface 3, so the uninflated trampoline can be folded into a compact condition for transport or storage.

When the tube 1 is inflated (conveniently by a pump) the trampoline assumes the shape shown in Figures 1, 2 and 3.

The internal pressure in the tube 1 tensions the tube wall and, in turn, tensions the bouncing surface 2. As a result of this tension, the bouncing surface applies to the tube 1 a force which tends to cause the tube 1 to contract radially inwardly, and this tendency is resisted by restraining means in the form of a steel tube formed into a hoop 4 or which is sufficiently rigid to withstand this radially inwardly directed force. The hoop 4 is enveloped within the tube 1 so that the tube 1 surrounds and protects the hoop 4 from above and from the outside of the trampoline, ensuring that a user cannot hit the hoop 4.

In cross-section (Figure 1), the tube 1 presents a convex and smoothly bulbous shape on its radially outer side. On its radially inner side, the tube presents two lobes 5 between which is a re-entrant portion at which the tube material is attached to the hoop 4.

To balance the force applied to the tube 1 by the tension in the bouncing surface 2, a rope 6 (or similar member capable of withstanding tension) passes through loops at the bottom of the tube 1, the rope 6 therefore encircling the underside of the tube 1 and being tensioned when the tube 1 is inflated.

The bouncing dynamics and low centre of mass effectively prevent the trampoline from over-toppling during normal use. The tension in the bouncing surface 2 is provided by the degree of inflation of the inflatable tube 1, making assembly and tensioning a simple matter of inflating the tube 1.

Figures 4, 5 and 6 illustrate a second embodiment which is similar to that of Figures 1, 2 and 3 but the restraining means are in this case constituted by two vertically spaced tubular steel hoops 4a, 4b which restrain the tube around its inner periphery. The bouncing surface 2 is attached to the tube around a circular seam line 3 tangential with the uppermost point of the tube crosssection, and a rope 6 is again provided to encircle the underside of the tube 1 in order to balance the tension applied to the tube 1 by the bouncing surface 2.

Figures 7, 8 and 9 illustrate a third embodiment which has an inflatable tube 1 of generally rectangular or square shape in plan, surrounding a rectangular or square bouncing surface 2 the four sides of which are bonded (around a seam line 3) to the respective sides of the tube at the top of the periphery thereof. In this case, the restraining means are constituted by a substantially rigid frame having a rectangular base plate 7 the underside of which engages the floor or ground on which the trampoline rests and from the upper surface of which project four inwardly angled walls 8. Each wall 8 abuts, on its outer surface, a corresponding side of the inflatable tube 1, the walls therefore providing an extensive reaction area and acting to prevent any tendency for opposite sides of the tube to move inwardly as a result of the tension in the bouncing surface 2.The tube attaches to the rigid frame at 13 so transmitting the tension from the bouncing surface to the frame. The provision of a rigid frame avoids the need for a separate member like the rope 6 of the other embodiments.

Unlike the previous embodiments which utilise a rigid frame or hoop as the restraining means, the embodiment of Figures 10, 11 and 12 has restraining means constituted by an inflatable component 9 which is surrounded by the toroidal tube 1 and forms a common inflatable volume therewith. The inflatable component 9 is defined between upper and lower walls 10, 11 interconnected by a series of circular concentric linking walls 12 each of which is apertured or perforated. The vertical extent of the inflatable component 9 is considerably less than the vertical extent of the inflatable tube 1, there being a space both between the bouncing surface 2 and the upper wall 10 of the component 9, and between the lower wall 11 and the ground or floor on which the trampoline rests. A rope 6 again encircles the underside of the tube.

In each of the described embodiments the force that provides the upward motion of the bouncing surface during use is provided by the inflatable means that store the energy of the downwards bounce. This connects to the bouncing surface in such a way that any downward motion of the surface decreases the volume of the inflatable means, thus increasing the pressure, which in turn provides the required upwards force. The geometry and construction are such that in each case the trampoline is unconditionally stable to a displacement of any of the components in any direction.

Claims

1. A trampoline comprising a bouncing surface spanning spaced regions of inflatable means which, on inflation, tensions the bouncing surface such that downward displacement of the bouncing surface reduces the volume of the inflatable means and thereby increases the pressure in the inflatable means, and restraining means which are operative, when the bouncing surface is tensioned on inflation of the inflatable means, to provide a restraining force which acts on the inflatable means to resist the tendency for the inflatable means to move in a manner which would result in a reduction of tension in the bouncing surface.

2. A trampoline according to claim 1, wherein the restraining means provide a restraining force which acts on the inflatable means to resist the tendency for the regions of the inflatable means to move towards one another.

3. A trampoline according to claim 1, wherein the inflatable means is constituted by an inflatable tube which extends around the complete periphery of the bouncing surface.

4. A trampoline according to claim 3, wherein the tube is in plan view square, rectangular or annular.

5. A trampoline according to claim 3 or 4, wherein the tube forms a common inflatable volume.

6. A trampoline according to any of the preceding claims, wherein the restraining means are inflatable.

7. A trampoline according to claim 6, wherein the internal volume of the restraining means is common with the internal volume of the inflatable means.

8. A trampoline according to claim 6, wherein the internal volume of the restraining means is separate from the internal volume of the inflatable means.

9. A trampoline according to claim 7, wherein the inflatable means is a toroidal inflatable tube which surrounds a circular inflatable compartment constituting the restraining means.

10. A trampoline according to any of claims 1 to 5, wherein the restraining means comprise a frame against which the inflatable means abuts, the frame being positioned so that it is protected by the inflatable means in such a way as to prevent a user hitting the frame.

11. A trampoline according to claim 10 wherein the inflatable means overlies the frame in the erected condition of the trampoline.

12. A trampoline according to claim 11, wherein the inflatable means additionally surround the frame around the outside thereof to provide lateral protection for the frame.

13. A trampoline according to claim 10, wherein two vertically spaced rings or hoops constitute the frame, the trampoline being circular.

14. A trampoline according to claim 10, wherein the trampoline is circular and the frame is in the form of a single ring or hoop which is wholly enclosed within an inflatable generally annular or toroidal tube constituting the inflatable means.

15. A trampoline according to claim 14, wherein the tube of the inflatable means in cross-section presents the shape of two lobes which adjoin at the point at which the material of the tube is attached to the ring or hoop.

16. A trampoline according to any of the preceding claims, wherein the bouncing surface is attached around its complete periphery to the inflatable tube forming the inflatable means.

17. A trampoline according to claim 16, wherein the attachment of the bouncing surface to the inflatable tube of the inflatable means is at or adjacent the highest point of the cross-sectional shape of the inflatable tube, a filamentary tension member, (such as a rope) interconnecting lower points of the tube to balance the force imparted to the tube by the tension in the bouncing surface.

18. A trampoline constructed and arranged substantially as herein particularly described with reference to any one of the alternative embodiments illustrated in the accompanying drawings.