US20260000928A1

US20260000928A1 - Trampoline Frame Structure

Info

Publication number: US20260000928A1
Application number: US19/127,120
Authority: US
Inventors: Tapio Mäkelä; Timo LUHTANIEMI; Jari Kiviniemi
Original assignee: Acon Finland Oy Ltd
Current assignee: Acon Finland Oy Ltd
Priority date: 2022-11-04
Filing date: 2023-10-27
Publication date: 2026-01-01
Also published as: AU2023374833A1; WO2024094917A1; EP4611908A1; FI20227136A1; FI130919B1

Abstract

This disclosure relates to a trampoline frame structure having a plurality of horizontal side frame members, a plurality of horizontal end frame members, a plurality of leg members and at least one U-shaped support member. The leg members are arranged vertically below the side frame members. The support member is arranged parallel to the end frame members between the leg members, which are opposite to each other on opposite sides of the mat, so that the support member is at a diagonal angle to the side frame members when viewed from the side.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national phase application of international application PCT/FI2023/000006, filed 27 Oct. 2023, which claims priority to Finnish patent application 20227136, filed Nov. 4, 2022, the content of the both of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to a frame structure for a trampoline comprising a substantially rectangular mat, and a plurality of spring elements arranged between the mat and the frame structure, which frame structure comprises a plurality of horizontal side frame members, a plurality of horizontal end frame members and a plurality of leg members, of which the side frame members and the end frame members are interconnected to form a base frame that circumferentially surrounds the mat and to which the spring elements are attached, and the leg members are arranged to raise the base frame above the ground.

Description of Related Art

Trampolines are commonly used in outdoor and indoor activities. Trampolines comprise a frame and a rebounding mat connected to the frame with stretching elements such as springs or similar. Furthermore, trampolines comprise legs or a frame structure that is connected to the frame to rise it above the ground.
There are different types of trampolines for different use. Trampolines for recreational use are generally used at home in backyards for jumping exercises and stunts on the said device. Such outdoor trampolines come in many shapes and sizes, however most are circular or rectangular with a diameter of 3 to 5 meters and the mat of said devices is situated at least 60 to 100 centimeters above the ground. On devices of this type, people attempt to jump as high as possible. The jumping characteristics of a trampoline, the bounce and performance, are generally determined by the characteristics of the chosen springs, the size of the mat and the characteristics of the frame structure. During jumping, the trampoline is subjected to forces that correspond to a multiple of the user's weight and the jump frequency can be up to 40 to 60 times per minute. The springs are used to receive and release the forces from the landing to boost another jump. In addition to the vertically acting forces, considerable horizontal forces or transverse forces can also act on the frame structure. Therefore, outdoor trampolines require a solid and rigid frame structure that can withstand a multitude of torsion forces.
In some trampolines, the frame structure consists of parts that are welded to each other to construct a solid structure. However, the large size of the welded trampoline frame structure makes it difficult and expensive to transport and since it cannot be disassembled, it occupies excessive space when stored. Because of these considerations, a frame structure for an outdoor trampoline is generally constructed from several separate transverse pipes and leg pipes that are connected to each other with joint sleeve structures in a detachable manner, so that the trampoline frame can be disassembled for transportation and storage. The pipes can be connected to the joint sleeve structures with some clamping arrangements, such as bolts or screws, which penetrate through both the joint sleeve structure and the end of the transverse pipe to fix them together. Such trampoline frame structures are disclosed for example by patent publications U.S. Pat. Nos. 4,339,123A, U.S. Pat. No. 7,494,444B2 and US20100240496A1. However, the structures described in the publications are not rigid enough to withstand without flexing and deformation the forces that act on the frame structure when the trampoline is in use. Because in sleeve joints there must be some clearance to allow for assembly, the joints cannot be made sufficiently tight to prevent flexing of the joints altogether during jumping. Clamping arrangements, such as bolts or screws, do not prevent such movement and flexing of the joints in all directions. The pipes and the joint sleeve structures contribute to the deformation differently, causing slight movements between the connection surfaces and these movements produce excessive noise. In addition to the noise caused by the movements of the joints, the movements and flexing of the joints has a negative effect on the bounce and performance of the trampoline. If the sleeve-joint couplings are very tight or have some clamping arrangements to prevent movements in all directions, the frame structure is cumbersome and complex to assemble.
There is a clear need for a rigid, durable, silent and easy to assemble trampoline frame structure.

BRIEF SUMMARY OF THE INVENTION

An object of the invention is a solution that can significantly reduce the disadvantages and drawbacks of the prior art. In particular, the object of the invention is a solution where a device is a trampoline frame structure that is rigid, durable, silent, and easy to assemble.
The objects of the invention are attained with a trampoline frame that is characterized by what is stated in the independent patent claim. Some advantageous embodiments of the invention are disclosed in the dependent claims.
The invention is a frame structure for a trampoline. The trampoline comprises a substantially rectangular mat and a plurality of spring elements arranged between the mat and the frame structure. The frame structure comprises a plurality of horizontal side frame members, a plurality of horizontal end frame members and a plurality of leg members. The side frame members and the end frame members are interconnected to form a base frame that circumferentially surrounds the mat and to which the spring elements are attached. The leg members are arranged substantially vertically below the side frame members to raise the base frame above the ground. The frame structure further comprises at least one U-shaped support member having upper corners and lower corners. The middle part of the support member is parallel to the end frame members between the leg members, which are opposite to each other on opposite sides of the mat. The side frame member comprises a fixing slot for the upper corner of the support member and the leg member comprises at least one attachment arrangement for the lower corner of the support member. The support member is fixed from its upper corners to the fixing slots of the side frame members and from its lower corners to the attachment arrangements of the leg members. The attachment arrangement for the lower corner of the support member is lower and closer to the corner of the trampoline than the fixing slot for the upper corner of the support member, so that the support member is at a diagonal angle to the side frame members when viewed from the side.
When reference is made in the text to the upper or the lower parts or respective directions such as down or up, or vertical or horizontal directions, a situation is described in which the trampoline according to the invention is in use, i.e. placed on ground or similar surface. Also, when reference is made to the front, rear, top or side parts or directions, the trampoline is placed similarly and in such a way that the front side is typically used to jump on the trampoline, and in case of a rectangular trampoline, the side is the longer side of the rectangular. When reference is made to the internal or external sides, the trampoline is placed similarly and the internal side is facing towards the center of the mat and the external side is facing outwards from the center of the mat.
The present invention relates to a frame structure for a trampoline comprising a substantially rectangular mat, and a plurality of spring elements arranged between the mat and the frame structure, the frame structure comprises a plurality of horizontal side frame members, a plurality of horizontal end frame members and a plurality of leg members, the side frame members and the end frame members are interconnected to form a base frame that circumferentially surrounds the mat and to which the spring elements are attached, and the leg members are arranged to raise the base frame above the ground. In one advantageous embodiment of the invention, the leg members are arranged substantially vertically below the side frame members, and the frame structure further comprises at least one U-shaped support member having upper corners and lower corners, and a part of the support member is parallel to the end frame members between the two leg members, which are opposite to each other on opposite sides of the frame structure. The side frame member comprises a fixing slot for the upper corner of the support member, and the leg member comprises at least one attachment arrangement for the lower corner of the support member. The support member is fixed from its upper comers to the fixing slots of the side frame members and from its lower corners to the attachment arrangement of the leg members. The attachment arrangement for the lower corner of the support member is lower and closer to the corner of the base frame of the trampoline than the fixing slot for the upper corner of the support member, so that the support member is sloping downwards towards the vertical plane of the end frame member.
In an embodiment of the frame structure, the base frame is stiffened in the horizontal direction by the support member, and leg members are configured to carry the vertical forces of the base frame. The support member is substantially rigid in the horizontal direction and the fixing of the upper corners of the support member to the fixing slot of the side frame members prevents movements and flexing of the joints of the base frame in the horizontal direction during jumping.
In a second embodiment of the frame structure, the distance between the upper corners of the support member is greater than the distance between the fixing slots of the opposing side frame members, so that fixing of the support member to the base frame forces the side frame members away from each other. The fixing of the support member to the base frame bends the side frame members and makes the shape of the base frame convex-crowned when viewed from the top, while after installation of the spring elements, the shape of the base frame returns to substantial rectangular. The crowning of the base frame caused by the support member compensates for the deflection caused by the spring elements. As a result, the joints of the base frame are straighter and there is less flexing and deformation. This arrangement removes clearances from the joints of the base frame, further stiffens the base frame and reduces movement of the joints and noise during jumping.
In a third embodiment of the frame structure, the tension of the spring elements is dimensioned in such a way that the shape of the base frame is kept substantially rectangular.
In a fourth embodiment of the frame structure, the angle of the lower corners of the support member is greater than 90 degrees, and fixing the support member to the attachment arrangement tightens the fixture of the leg members. This configuration tilts the lower end of the leg member inwards and at the same time removes the clearances from the joints of the leg member.
In a fifth embodiment of the frame structure, the support member comprises a tubular inner support and a tubular outer support that are interlinked with linkage bars to form a rigid lattice structure. The lattice structure makes the support member rigid in the horizontal direction.
In a sixth embodiment of the frame structure, the support member comprises a rigid plate that is fixed between the inner support and the outer support to stiffen the support member.
In a seventh embodiment of the frame structure, the leg member is U-shaped tubular leg comprising two vertical pipes having upper ends and lower ends, one horizontal pipe having a first end and a second end, the horizontal pipe comprising upwardly directed sleeve portions at its both ends, to which the lower ends of the vertical pipes are attached, and at the upper ends of the vertical pipes they comprise a similar sleeve portion, at which the upper ends of the vertical pipes are attached to the side frame members.
In an eighth embodiment of the frame structure, the leg member comprises a plurality of attachment arrangements for the lower corner of the support member, and the upper corners of the support member are pivotally coupled to the fixing slot of the side frame members, so that the height of the frame structure and the distance between the base frame and the ground can be altered by changing the length of the vertical pipes of the leg members, or by removing the vertical pipes and pivoting the support member and changing the fixing point of the lower corner of the support member to the other attachment arrangement of the leg member. This makes the frame structure easily adjustable for different use like inground or sunken trampolines or trampolines for plays of small children. In one advantageous embodiment of the invention, the vertical pipe is a telescopic pipe structure that comprises an outer pipe, an inner pipe and a fixing means. The inner pipe is fitted into the outer pipe and adapted to move relative to the outer pipe. The outer pipe, the inner pipe and the fixing means are configured in such a way that the height of the frame structure is adjustable by varying the length of the of the telescopic pipe structure of the vertical pipes.
In a nineth embodiment of the frame structure, the frame structure comprises an elongated support bar having a first end and a second end of the support bar, and the first end of the support bar is fixed to the support member and the second end of the support bar is connected to the leg member. In one advantageous embodiment of the invention, the second end of the support bar is fixed to the horizontal pipe of the leg member.
In a tenth embodiment of the frame structure, the second end of the support bar is fixed to the leg member, and the fixing point of the second end of the support bar is close to the lower corner of the leg member, which is further away from the corner of the trampoline.
In an eleventh embodiment of the frame structure, the support bar is fixed between the leg member and the tubular inner support.
In a twelfth embodiment of the frame structure, the frame structure comprises four leg members and two support members.
In a thirteenth embodiment of the frame structure, the support member comprises two end elements and an intermediate element that is arranged between the end elements and fixed to the end elements with bolts.
In a fourteenth embodiment of the frame structure, the side frame member comprises two end parts and an intermediate part that is arranged between the end parts and the end part comprises fittings for the leg member and for the end frame member.
In a fifteenth embodiment of the frame structure, the intermediate part is a telescopic pipe structure comprising an outer pipe, two inner pipes, the inner pipes having inner ends and outer ends, the inner ends are arranged to be attached to the end parts, the outer ends are fitted into the outer pipe and adapted to move relative to the outer pipe, and a fixing means is configured in such a way that the size of the base frame can be extended by extending the length of the telescopic pipe structure of the intermediate part. This makes the frame structure easily adjustable for different mat sizes.
It is an advantage of the invention that it provides a trampoline frame structure that is stable, durable, rigid, and can be easily assembled for storage or transportation. Also, the frame structure is modular and can be designed lighter without losing the bouncing properties of the trampoline.
It is a further advantage of the trampoline frame structure that it is silent when the trampoline is used.
It is also an advantage of the trampoline frame that it is safe to use and easily adjustable for different use.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Further advantageous features and details of the various embodiments of this disclosure will become apparent from the ensuring description of a preferred exemplary embodiment or embodiments and further with the aid of the drawings. The features and combinations of features recited below in the description, as well as the features and feature combination shown after that in the drawing description or in the drawings alone, may be used not only in the particular combination recited by also in other combinations on their own without departing from the scope of the disclosure.

FIG. 1 shows an example of a trampoline according to an embodiment,

FIG. 2 shows an example of a frame structure of the trampoline as presented in FIG. 1 ,

FIG. 3 shows the frame structure of the trampoline presented in FIG. 2 as seen from the side,

FIG. 4 shows the frame structure of the trampoline presented in FIG. 2 as seen from the end,

FIG. 5 shows the frame structure of the trampoline presented in FIG. 2 as seen from above,

FIG. 6 shows an example of a support member of the frame structure as presented in FIG. 2 ,

FIG. 7 shows the support member presented in FIG. 6 when disassembled,

FIG. 8 shows an example of a base frame of the frame structure presented in FIG. 2 as seen from above,

FIG. 9 shows the side frame member presented in FIG. 8 ,

FIG. 10 shows the base frame presented in FIG. 8 when disassembled,

FIG. 11 shows an example of a leg member of the frame as presented in FIG. 2 ,

FIG. 12 shows the leg member presented in FIG. 11 when disassembled,

FIG. 13 shows the frame structure presented in FIG. 2 in a lowered position, and

FIG. 14 shows a detail of the trampoline presented in FIG. 1 as seen from above.

DETAILED DESCRIPTION OF THE INVENTION

As used throughout the present disclosure, unless specifically stated otherwise, the term “or” encompasses all possible combinations, except where infeasible. For example, the expression “A or B” shall mean A alone, B alone, or A and B together. If it is stated that a component includes “A, B, or C”, then, unless specifically stated otherwise or infeasible, the component may include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C. Expressions such as “at least one of” do not necessarily modify an entirety of the following list and do not necessarily modify each member of the list, such that “at least one of “A, B, and C”.
The embodiments in the following description are given as examples only and someone skilled in the art can carry out the basic idea of the invention also in some other way than what is described in the description. Though the description may refer to a certain embodiment or embodiments in several places, this does not mean that the reference would be directed towards only one described embodiment or that the described characteristic would be usable only in one described embodiment. The individual characteristics of two or more embodiments may be combined and new embodiments of the invention may thus be provided.
FIGS. 1 and 14 show an embodiment of a trampoline 100 using a frame structure 101 according to the invention. FIG. 1 shows an overview of the trampoline and FIG. 14 shows a corner of the trampoline.
The trampoline 100 comprises the frame structure 101, a mat 102, and a plurality of spring elements 103. The trampoline is rectangular and has sides of the trampoline and ends of the trampoline. In this embodiment, the sides of the trampoline are longer than the ends of the trampoline. The trampoline comprises four corners of the trampoline. The mat is substantially rectangular. The spring elements are between the mat and the frame structure, i.e. they are attached both to the mat and the frame structure. The spring elements are, for example, metal springs, rubber structures or other resilient members. Advantageously, the spring elements are detachable. The spring elements provide the bouncing effect for the mat and thus for the trampoline. In FIG. 1 , additional padding is attached to the frame structure in such a way that it covers the gap between the mat and the frame structure.
The frame structure 101 comprises a base frame (not numbered in FIG. 1 or 14 ), leg members 106 and support members 108. The leg members are configured to keep the base frame above the ground. In this embodiment, the frame structure further comprises support bars 109. The base frame comprises horizontal side frame members 104 and horizontal end frame members 105. These frame members form a rectangular structure in the upper part of the frame structure. In this embodiment, the support member comprises a rigid plate 186 for stiffening the support member. FIG. 2 shows an example of the frame structure 101. The frame structure comprises the base frame 107, four leg members 106, two support members 108 and four support bars 109.
The base frame 107 is a rectangular structure comprising horizontal side frame members 104 and horizontal end frame members 105. The end frame members form at least parts of the ends of the trampoline and the side frame members form at least parts of the sides of the trampoline. The side frame members and end frame members are connected to each other at the corners of the base frame and at the same time at the corners of the frame structure 101 and the trampoline.
The leg members 106 are rectangular structures comprising three pipes, i.e. one side of the rectangular shape is open. This means that the leg member resembles a U-shape. The leg members are connected to the base frame 107 in such a way that the open side is upwards. The leg members are substantially vertical and they are below the side frame members 104. The plane of the leg member is parallel to the longitudinal axis of the side frame member, i.e. the leg members are parallel to the sides of the trampoline. The leg members are connected to the side frame members in such a way that the one end of the leg member is connected to the end of the side frame member. This means that said end of the leg member is a part of one corner of the trampoline. The leg member comprises a horizontal part between two vertical parts. The upper ends of the vertical parts are connected to the side frame members. When the trampoline is positioned for use, i.e. placed on a surface, the horizontal part of the leg members is on said surface.
The support member 108 is a U-shaped structure comprising two arms and a bottom part between the arms. This means that the bottom parts interconnects the arms. The support member has upper corners and lower corners. The upper corners are the tips of the arms of the U-shape and the lower corners are connection points between the arms and the bottom part. The support member is connected to the frame structure 101 in such a way that the bottom part is parallel to the end frame members 105. The support member is between two leg members 106, which are opposite to each other. This means that said leg members are on the opposite sides of the trampoline. The upper corners of the support member are connected to the side frame members 104 in such a way that one upper corner is connected to one side frame member and another upper corner is connected to another side frame member. The lower corners are similarly connected to the leg members. One lower corner is connected to one leg member and another lower corner is connected to another leg member. The connection point of the lower corner is closer to the corner of the trampoline than the connection point of the upper corner, i.e. the lower corner is closer to the end side of the trampoline than the upper corner. This means that the support member is sloping downwards towards the vertical plane of the end frame member 105.
In this embodiment, there are two support members 108 and they are positioned at the ends of the trampoline. In some embodiments, there is one support member. The support members provides rigidity to the frame structure 101, and more specifically, horizontal rigidity.
The support bar 109 is an elongated structure having a first end of the support bar and a second end of the support bar. The first end of the support bar is connected to the support member 108 and the second end of the support bar is connected to the leg member 106. The connecting point of the second end of the support bar is close to the lower corner of the leg member, which lower corner is further away from the corner of the trampoline. The support bar provides rigidity between the support member and the leg member and spreads out stress forces. The support bar is positioned in such a way that the second end is connected to the horizontal part of the leg member and the connection point of the first end on the support member is higher than the connection point of the second end. This means that the support bar slopes upwards towards the end of the trampoline.
FIG. 3 shows the frame structure 101 as seen from the side. Two leg members 106 are connected to the ends of the side frame member 104. Side frame member has two connection points for the leg member: one connection point at the corner of the frame structure (the corner of the base frame) and another connection point that is towards other corner of the frame structure. The side frame member comprises a fixing slot 143 for connecting the upper corner 181 of the support member to the frame structure. In this embodiment, there are two fixing slots in one side frame member. The fixing slot and the upper corner are configured in such a way that the support member is pivotally coupled to the side frame member 104 when the fixing slot and the upper corner are interconnected. One end of the leg member is connected near the fixing slot. In some embodiments, there is a leg member attachment arrangement near the fixing slot. The leg member attachment arrangement and the fixing slot are configured in such a way that the connection point of the leg member and the connection point of the upper corner of the support member 108 are practically at the same point when considering the stress force distribution in the frame structure. The support bar 109 is between the leg member 106 and the support member 108. The leg member comprises at least one attachment arrangement 161 for the lower corner of the support member. The attachment arrangement is on the horizontal part of the leg member. The attachment arrangement is positioned in such a way that it is nearer to the corner of the trampoline (i.e. nearer to the end of the trampoline) than the connection point of the support bar on the leg member. In this embodiment, the attachment arrangement and the connection point of the support bar are on opposing ends of the horizontal part of the leg member. The attaching arrangement is a conventional structure for attaching two pipelike structures. For example, the attaching arrangement may be a slot for receiving an extension on the support member. Naturally, there are many other ways to implement the attaching arrangement.
FIG. 4 shows the frame structure 101 as seen from the direction of the end of the trampoline. Two leg members 106, the end frame member 105 and the bottom part of the support member 108 form a rectangular shape. It must be noted that the shape is virtual because the horizontal bottom part of the support member is not on the same level as the leg members and the end frame member.
FIG. 5 shows the frame structure 101 as seen from above. The rectangular base frame comprises two horizontal side frame members 104 and two horizontal end frame member 105. The upper comers of the support member 108 are connected to the side frame members. The lower corners of the support member are connected to the leg members. Because side frame members and leg members define the sides of the trampoline, the support member is between the sides of the trampoline. In this embodiment, the support member does not extend to the end of the trampoline, i.e. to the vertical level of the end frame member. In this embodiment, the distance between the upper corners of the support member is greater than the distance between the fixing slots of the opposing side frame members so that the fixing of the support member to the base frame bends the side frame members and makes the shape of the base frame convex-crowned when viewed from the top. After installation of the spring elements, the shape of the base frame returns to substantial rectangular. The support bar 109 is connected to the support member in such a way that the connection point on the support member is closer to the longitudinal center line of the trampoline than the connection point on the leg member. This means that the connection points of two opposing support bars on the support member are closer to each other than the connection points on the leg members. FIG. 6 shows the support member 108. The support member is a U-shaped structure. The upper corners 181 are at the tips of the arms of the U. The lower corners 182 are between the arms and the bottom part of the U. The support member comprises two arm parts, a tubular inner support 183 and a tubular outer support 184. The inner support extends from one upper corner to another upper corner. The outer support extends from one lower corner to another lower corner. The outer support forms the bottom part of the U. The outer support is a straight structure. The inner support curves towards the outer support. The inner support does not extend to the level of the outer support. The inner support part comprises a straight inner support part, and the straight inner support part is parallel to the outer support. Between the inner support and the outer support are linkage bars 185. In this embodiment, there are linkage bars also between the arm parts and inner support. The linkage bars, the inner support and the outer support form a rigid lattice structure. In some embodiments, the rigid plate for stiffening the support member is positioned between the inner support and the outer support. The support bar is connected to the inner support part.
The angles of the lower corners 182 of the support member 108 are greater than 90 degrees, and fixing the support member to the attachment arrangement tightens the fixing of the leg members. This means that when the support member is not installed to the frame structure, the distance between the upper corners 181 is longer than the distances between the lower corners 182.
The support part 108 comprises parts that are detachable from each other. FIG. 7 shows the support member disassembled. The support part comprises two end elements 187 and an intermediate element 188. The intermediate element is between the end elements. The end element comprise the upper corner and the lower comer. The dividing point between the end element and the intermediate element is chosen in such a way that the intermediate element comprise at least two linkage bars 185.
FIG. 8 shows the base frame 107 as seen from above. The base frame defines the overall shape of the trampoline. The base frame comprises two side frame members 104 and two end frame members 105. They are positioned in a rectangular shape where sides of the base frame are longer than the ends of the base frame.
FIG. 9 shows the side frame member 104 as seen from the side. The side frame member 104 comprises two end parts 141 and an intermediate part 142 between the end parts. Said parts are detachable from each other. The corners of the base frame are in the end parts. This means that the end part extends partly on the end side of the trampoline. The end part comprises two fittings: a first fitting 144 and a second fitting 145. The fittings are for connecting the leg member to the end part and at the same time to the base frame. The second fitting is on the corner of the base frame. The first fitting is positioned near the fixing slot 143 in such a way that the connection points of the leg member and the support member are practically at the same point when considering the dimensions and stress force distributions of the frame structure.
FIG. 10 shows the base frame 107 in a disassembled state. The base frame comprises two end frame members 105, four end parts 141 and two intermediate parts 142. In some embodiments, the intermediate part is a telescopic pipe structure. In some embodiments, the intermediate part comprises an outer pipe and two inner pipes. The inner pipes have inner ends and outer ends. The inner ends are configured to be attached to the end parts 141. The outer ends are fitted into the outer pipe and adapted to move relative to the outer pipe. The intermediate part further comprises a fixing means configured in such a way that the size of the base frame 107 is extendable by extending the length of the telescopic pipe structure of the intermediate part.
FIG. 11 shows the leg member 106. The leg member is a U-shaped structure having two vertical arms and the horizontal part between the horizontal parts. The terms ‘vertical’ and ‘horizontal’ describe a situation where the leg member is attached to the side frame member and to the trampoline, and the trampoline is ready for use. In the horizontal part is the attachment arrangement 161 for attaching the lower corner of the support member to the leg member. In some embodiments, the horizontal part comprises several attachment arrangements.
FIG. 12 shows the leg member 106 in a disassembled state. The leg member comprises a horizontal pipe 163 and two vertical pipes 162, and when they are interconnected, they form the horizontal part and vertical arms correspondingly. The attachment arrangement 161 is positioned on the horizontal pipe. The ends of the horizontal pipe are curved upwards, and they define the direction of vertical pipes. This means said curved parts are vertical. The horizontal pipe comprises upwardly directed sleeve portion 164 at its both ends. The lower ends of the vertical pipes are configured to be fitted to the sleeve portions. In this embodiment, the diameter of the sleeve portion is less than the diameter of the other parts of the curved part. At the upper ends of the vertical pipes comprise a corresponding sleeve portion from which the upper ends of the vertical pipes are attached to the side frame members.
In some embodiments, the vertical pipe 162 is a telescopic pipe structure. In some embodiments, the vertical pipe comprises an outer pipe and an inner pipe. The outer pipe has lower end and higher end. The lower end is configured to be attached to the sleeve portion 164 of the horizontal pipe 163. The inner pipe is fitted into the higher end of the outer pipe and adapted to move relative to the outer pipe. The vertical pipe further comprises a fixing means configured in such a way that the height of the leg members is adjustable by varying the length of the telescopic pipe structure of the vertical pipes.
FIG. 13 shows the frame structure 101 as in a lowered position. The heights of the leg members 106 are shortened by removing the vertical pipes of the leg members and the sleeve portions of the horizontal pipes are attached to the side frame member 104. Because the heights of the leg members are shortened, the heights of the frame structure and the trampoline are shortened, too. The upper corner of the support member 108 is attached to the fixing slot 143. The lower corner 182 is detached from the attachment arrangement and is attached to the leg member nearer to the end side of the trampoline. This attachment is similar to the attachment arrangement but can implemented differently. The frame structure in the lowered position can be used for example for inground or sunken trampolines. Also, the height of the trampoline can be adjusted by replacing the vertical pipes with vertical pipes of a different length or by using the vertical pipes comprising an adjustable telescopic pipe structure. The frame structure with different height can be used for example for trampolines with different user weight limits.
Finally, it should be noted that the description of the invention and the exemplary embodiments are not to be understood as limiting in terms of a particular physical realisation of the invention. The scope of protection of the present invention is given by the claims and is not limited by the features illustrated in the description or shown in the figures.

Claims

1. A frame structure for a rectangular trampoline, the frame structure comprising sides of the trampoline and ends of the trampoline,

wherein sides of the trampoline are longer than the ends of the trampoline,

wherein the trampoline comprises a substantially rectangular mat, and a plurality of spring elements arranged between the mat and the frame structure,

wherein the frame structure comprises a plurality of horizontal side frame members for the sides of the trampoline, a plurality of horizontal end frame members for the ends of the trampoline, and a plurality of U-shaped leg members,

wherein the side frame members and the end frame members are interconnected to form a base frame that circumferentially surrounds the mat and on which the spring elements are attached, and

wherein the leg members are arranged to raise the base frame above the ground and are arranged substantially vertically below the side frame members and plane of the leg member is parallel to longitudinal axis of the side frame member,

wherein the frame structure further comprises at least one U-shaped support member having upper corners and lower corners, and a part of the support member is parallel to the end frame members between two leg members, which are opposite to each other on opposite sides of the frame structure,

wherein the side frame member comprises a fixing slot for the upper corner of the support member,

wherein the leg member comprises at least one attachment arrangement for the lower corner of the support member, and

wherein the support member is fixed at its upper corners to the fixing slots of the side frame members and at its lower comers to the attachment arrangement of the leg members, and the attachment arrangement for the lower corner of the support member is lower and closer to the corner of the base frame of the trampoline than the fixing slot for the upper corner of the support member, so that the support member is sloping downwards towards the vertical plane of the end frame member.

2. The frame structure according to the claim 1, wherein the base frame is stiffened in the horizontal direction by the support member, and leg members are configured to carry the vertical forces of the base frame.

3. The frame structure according to the claim 2, wherein a distance between upper corners of the support member is greater than the distance between fixing slots of the opposing side frame members, so that fixing the support member to the base frame forces the side frame members away from each other.

4. The frame structure according to the claim 3, wherein the tension of the spring elements is dimensioned in such a way that the shape of the base frame is kept substantially rectangular.

5. The frame structure according to any claim 1, wherein an angle of the lower corners of the support member is greater than 90 degrees, and fixing of the support member to the attachment arrangement tightens the fixture of the leg members.

6. The frame structure according to claim 1, wherein the support member further comprises a tubular inner support and a tubular outer support that are interlinked by linkage bars to form a rigid lattice structure.

7. The frame structure according to the claim 1, wherein the support member further comprises a rigid plate that is fixed between the inner support and the outer support to stiffen the support member.

8. The frame structure according to claim 1, wherein the leg member comprises two vertical pipes having upper ends and lower ends, one horizontal pipe having a first end and a second end, the horizontal pipe comprises an upwardly directed sleeve portion at its both ends, to which the lower ends of the vertical pipes are attached, and the upper ends of the vertical pipes comprise a similar sleeve portion at which the upper ends of the vertical pipes are attached to the side frame members.

9. The frame structure to according to the claim 8, wherein:

the leg member comprises a plurality of attachment arrangements to the lower corner of the support member, and

the upper corners of the support member are pivotally coupled to the fixing slot of the side frame members so that the height of the frame structure and the distance between the base frame and the ground can be altered by varying the length of the vertical pipes of the leg members or by removing the vertical pipes and pivoting the support member and changing the fixing point of the lower corner of the support member to the other attachment arrangement of the leg member.

10. The frame structure according to claim 8, wherein the frame structure further comprises an elongated support bar having a first end and a second end of the support bar, and the first end of the support bar is connected to the support member and the second end of the support bar is connected to the leg member.

11. The frame structure according to the claim 10, wherein the connecting point of the second end of the support bar is close to the lower corner of the leg member, and the lower corner of the leg member is the corner that is further away from the corner of the trampoline.

12. The frame structure according to claim 1, wherein the frame structure comprises four leg members and two support members.

13. The frame structure according to claim 1, wherein the support member comprises two end elements and an intermediate element that is between the end elements.

14. The frame structure according to claim 1, wherein the side frame member further comprises two end parts and an intermediate part that is arranged between the end parts and the end part comprises fittings for the leg member and the end frame member.

15. The frame structure according to the claim 14, wherein the intermediate part is a telescopic pipe structure comprising an outer pipe, two inner pipes, the inner pipes having inner ends and outer ends, the inner ends are arranged to be attached to the end parts, the outer ends are fitted into the outer pipe and adapted to move relative to the outer pipe, and a fixing means configured in such a way that the size of the base frame can be extended by extending the length of the telescopic pipe structure of the intermediate part.