Patent Description:
Trampolines are a well known type of play apparatus that comprise a jumping mat attached to a trampoline frame with a biasing means that holds the jumping mat under tension. Historically, helical springs have been used, but recently some trampolines, in particular mini trampolines, have been provided with mats held under tension by other means such as one or more bungee cords. The trampoline industry has found that in some configurations bungee cords have advantages over trampolines with metal springs, helical springs, fibre rods or leaf springs. Additionally, although the toy safety standard EN71 does not distinguish between different types of springs vs elastic connectors such as bungee cords, some end users have a preference for bungee cords or elastic connectors over traditional springs. However, until now bungee cords, even individual bungee cords, are frustrating to use to assemble a trampoline, and in particular for larger trampolines, it is extremely difficult to obtain the required tension in the jumping mat.

Requiring each individual bungee cord to be knotted is fiddly, and it is at best extremely difficult for an adult to tie bungee cords when they are stretched to provide adequate tension for the jumping surface of the trampoline, even for mini trampolines of the "rebounder" category, which do not require as high a tension as larger trampolines. For larger trampolines, the difficulty increases.

<CIT>) teaches away from a prior arrangement illustrated in <FIG> of this document on the basis that it is not safe and is difficult to use. Lengths of elastic rope have their ends fastened together to form a loop, in which the fastened ends cannot pass through a hole in a plastic connecting piece. In a first step, the remainder of the loop passes through the hole and is then looped under a curved pipe of the trampoline frame and through an edge portion of the trampoline jumping mat before being pulled back towards the connector and over its top to sit in a groove that runs around the outside of the connector.

<CIT>) has a plurality of connecting blocks (<FIG>) each fastened to the edge of the trampoline jumping mat by a strap that passes through a fixing hole. A length of elastic rope has its ends connected by a stopper that cannot pass through a threading hole of the connecting block. A loop of elastic rope passes through the threading hole, around the trampoline frame, and is then pulled back to the connecting block to be received in a hanging slot. No part of connecting block is capable of being hooked to the frame. It should also be noted that at maximum tension, the loop of elastic rope has to be pulled away from the user towards the hanging slot in the connecting block, which is difficult to achieve. Should the user let go prematurely or the loop miss the hanging slot, the loop will snap back and likely hit the user.

<CIT>) is concerned with a top cap for a trampoline netting pole. The trampoline mat itself is mounted to the frame by conventional helical springs (See Fig.). The safety net has what is described as a top rim which drops into a grove in the top cap. Rotating this slightly prevents the rim from readily coming out. There is also an aperture for receiving spring loaded pins.

<CIT>) is concerned with a connector (Figs 5A and 5B) useful in joining a trampoline mat to the frame using elastic cord. While the connector appears to have a through opening, this is in the form of a slot and is provided for permanently mounting the connector to the edge of the trampoline mat by webbing. This document also discloses apertures or side sockets with side openings to allow an end portion of an elastic cord to enter and to be held in place by knots. An intermediate portion of the elastic cord is looped around the trampoline frame and pulled back to the connector to be retained in a loop retaining feature. Only the elastic cord itself passes around the frame. There is no hook or other feature of the connector capable of hooking over the trampoline frame. Various other connectors are shown in other figures of this document, but they all work in a similar fashion, with the connector always remaining remote from the trampoline frame. Again it will be noted that at maximum tension, the loop of elastic cord has to be pulled back from the frame to the connector away from the user. Should the user let go of the elastic cord too soon so that it slips out of the retaining feature <NUM>, it will likely snap back and hit the user.

<CIT>) discloses mounting a trampoline mat to a frame by loops of elastic cord each cooperating with a connector. A number of differing geometries are discussed for the connector. In none of these is any part of the connector hooked over the frame. The only thing that goes around the frame are loops of the elastic cord.

The present disclosure results from Applicant's work seeking to provide improved apparatus for and methods for safely attaching a trampoline jumping mat to a trampoline frame in a manner that is both simple and safe for the person or persons assembling the trampoline, and for persons replacing parts or maintaining the trampoline, and which also results in an enjoyable jumping experience for persons jumping on the trampoline. In particular, this development is relevant to the use of elastic connectors such as bungee cords even in larger trampolines.

According to a first aspect of this disclosure, we provide a method for attaching a trampoline jumping mat to a trampoline frame using:.

Preferably, step "a" is carried out before step "b", but alternatively step "b" could be carried out before step "a".

The elastic connector comprises a single loop of elastics material, including a knot or other suitable fastening which is incapable of passing through the aperture in the clip.

Preferably, the method is repeated with a plurality of clips and a plurality of elastic connectors.

According to a second aspect of this disclosure, there is provided a method for assembling a trampoline, the method comprising: attaching a trampoline jumping mat to a trampoline frame according to the aforesaid method.

According to a third aspect of this disclosure, there is provided a clip for attaching a trampoline jumping mat having an edge provided with a plurality of openings to a trampoline frame with the aid of an elastic connector formed into a loop by fastening its ends together, the clip comprising: an aperture sized to enable the loop but not its fastened ends to be passed through the aperture around the frame and through an opening at the jumping mat edge; and the clip further comprising a protrusion to which the loop can be fastened after passing around the frame and through an opening; the clip further comprises a hook adapted to hook over a portion of the trampoline frame to thereby attach the clip to the trampoline frame, so that, in passing around the trampoline frame, the loop also passes around the hook.

Preferred embodiments of the above clip have one or more of the following features: The fastener is a protrusion around which a portion of an elastic connector can be looped. The clip is made from one or more of: nylon, acetal, polypropylene, high impact polystyrene, polyethylene (in particular low-density polyethylene (LDPE) or high-density polyethylene (HDPE)), or acrylonitrile butadiene styrene (ABS). Most preferably the clip is made from nylon. The clip is moulded, more preferably the clip is injection moulded. The clip is 3D printed. The hook of the clip comprises a groove for holding an elastic connector in a preferred position. The groove is positioned adjacent to the aperture. The groove comprises two or more sub-grooves, each sub-groove being arranged to hold a portion of an elastic connector in a preferred position. The clip is formed in one piece. The hook is shaped to cooperate with the frame of the trampoline.

According to a fourth aspect of this disclosure, there is provided a kit for attaching a trampoline jumping mat to a trampoline frame, the kit comprising one or more of the aforesaid clips, and an equal number of elastic connector(s) for use with the clip(s).

According to a fifth aspect of this disclosure, there is provided a trampoline assembled by use of the aforesaid clips and elastic connectors.

Preferred embodiments of apparatus for and methods for safely attaching a trampoline jumping mat to a trampoline frame in accordance with our teachings are described hereinbelow by way of example only with reference to the accompanying drawings in which:.

<FIG> show a preferred embodiment of a clip <NUM> for attaching a trampoline jumping mat <NUM> to a trampoline frame <NUM>. Clip <NUM> has a hook <NUM> for attaching clip <NUM> to a trampoline frame <NUM> according to the method depicted in <FIG>. Clip <NUM> also includes an aperture <NUM> which enables an elastic connector <NUM> to be passed through the aperture <NUM> and around both the hook <NUM> and the frame <NUM> of a trampoline. Clip <NUM> further comprises a fastener <NUM> to which the elastic connector <NUM> can be fastened. As shown in the Figures, in the preferred embodiment of clip <NUM>, fastener <NUM> is a protrusion around which a loop of elastic connector <NUM> can be looped.

A preferred method for attaching a trampoline jumping mat to a trampoline frame is depicted in <FIG>, using a clip <NUM> comprising an aperture <NUM>, the clip <NUM> further comprising a hook <NUM> for attaching the clip <NUM> to the trampoline frame <NUM>; and an elastic connector <NUM>, which in Applicant's preferred embodiment is a bungee cord, comprising a first portion <NUM> and a second portion <NUM>, the first portion <NUM> comprising a loop. <FIG> depicts the method step of passing part of the elastic connector <NUM> through the aperture <NUM> in the clip <NUM>. The method step of attaching the clip <NUM> to the frame <NUM> using the hook <NUM> is not shown, but it will be appreciated that hook <NUM> can simply be hooked over frame <NUM> either before or after part of the elastic connector is passed through aperture <NUM>.

The trampoline frame partially shown in <FIG> has a generally circular cross section as shown at section <NUM>-<NUM>, and hook <NUM> is shaped to accommodate part of frame <NUM>. It is generally preferred that trampolines have a circular cross section for their frames, but where a clip is required to attach a jumping mat to the frame of a trampoline with a frame having a cross section other than circular, the shape of the hook could be adjusted to co-operate with the shape of the frame. "Co-operate" does not mean that the general shape of the hook has to match the cross section of the frame, it only needs to be functionally compatible with the frame with which it is intended to be used.

<FIG> shows the immediate result of method step "c", the trampoline frame being omitted from the view for clarity. First portion <NUM> of elastic connector <NUM> has been passed around both hook <NUM> and frame <NUM>. The second portion <NUM> of elastic connector <NUM> is then connected to the trampoline jumping mat <NUM>, as shown in <FIG>. In this preferred embodiment, the trampoline mat comprises an opening <NUM>, and connection to the jumping mat <NUM> is achieved by passing the second portion <NUM> of the elastic connector <NUM> through the opening <NUM> in the trampoline jumping mat <NUM>, and attaching the second portion <NUM> of the elastic connector to the clip <NUM> by looping second portion <NUM> around a protrusion which is a fastener <NUM>.

The elastic connector comprises a single loop of elastics material, optionally including a knot or other suitable fastening which cannot pass through aperture <NUM>, in which one part of the single loop is considered to be the first portion and another part of the single loop is considered to be the second portion, as shown in the figures. One particular benefit of this is that the knot can be positioned within the clip, reducing access to the knot, which provides benefits both to user safety and to the appearance of the trampoline.

Clip <NUM> in Applicants' preferred embodiment is made from nylon, but alternative materials, including but not limited to: acetal, polypropylene, high impact polystyrene, polyethylene (in particular low-density polyethylene (LDPE) or high-density polyethylene (HDPE)), or acrylonitrile butadiene styrene (ABS) would also be suitable. Clip <NUM> in Applicants' preferred embodiment is injection moulded, but other manufacturing methods would be suitable, including 3D printing. Clip <NUM> in Applicants' preferred embodiment has a groove <NUM> which helps to keep elastic connector <NUM> in the desired position, and prevent elastic connector <NUM> slipping off the hook <NUM>. Groove <NUM> extends from a position adjacent to aperture <NUM>. As the part of elastic connector <NUM> that is passed around the hook <NUM> of clip <NUM> has two bungee strands, in the preferred embodiment, groove <NUM> has two sub-grooves <NUM> and <NUM> to each receive one bungee strand in their preferred positions. Sub-grooves <NUM> and <NUM> are separated by a raised portion <NUM>.

The above description relates to a single point of attachment of a jumping mat of a trampoline to the frame of a trampoline. It will be preferable to have a plurality of points of attachment between the mat and the frame. Most preferably, each of the plurality of points of attachment is made by using a clip and a connector as described herein. Alternatively, where a plurality of points of attachment are desired between a jumping mat of and a frame of a trampoline, some but not all of the connections can be provided according to the method described herein or using clips as described herein. By way of non-limiting example, this could be the case when users want to replace a single connection on their trampoline without replacing other connections, or when there are two or more categories of connection between the jumping mat and the trampoline frame. For example, in a trampoline that requires connections both around the circumference of the jumping mat and also at points not on the circumference of the mat, different attachment means could be used to fulfil the different requirements of those different locations. For example, the present arrangement could preferentially be used in areas where children could accidentally come into contact with the connectors, and springs or bungees attached in an alternative manner could be used in areas where users, in particular children, would not be likely to come into contact with the connectors.

An advantage of providing clip(s) separately from both the mat and the frame is that this allows for individual parts to be replaced without requiring replacement of other parts. Additionally, Applicants' method of attaching a jumping mat to a frame allows an end user to attach the mat by pulling on a soft elastic connector, rather than pulling on the clip itself, as in previously proposed trampolines. Requiring an assembler to pull on the clip itself can result in assemblers getting their fingers trapped between the clip and the frame, or even in a clip being projected by the elastic if user error occurs. As Applicants' clip is safely hooked to the frame before the user has to stretch the elastic connector to connect the mat to the frame in steps "d" and "e", there is no risk of the clip coming free and potentially injuring an assembler during assembly of the trampoline.

Claim 1:
A method for attaching a trampoline jumping mat (<NUM>) to a trampoline frame (<NUM>) using:
at least one clip (<NUM>) comprising an aperture (<NUM>), the clip (<NUM>) further comprising a hook (<NUM>) for attaching the clip (<NUM>) to the trampoline frame (<NUM>);
and at least one elastic connector (<NUM>) comprising a length of elastic material with two ends;
the two ends being connected together so that the elastic material forms a loop capable of passing through the aperture (<NUM>) in a clip (<NUM>) with a portion comprising the ends of the material fastened together which portion cannot pass through the aperture (<NUM>);
the edge of the trampoline jumping mat (<NUM>) being provided with a plurality of through openings (<NUM>);
the method comprising the steps of:
"a". passing the loop of the elastic connector (<NUM>) through the aperture (<NUM>) in the clip (<NUM>);
"b". attaching the clip (<NUM>) to the frame (<NUM>) using the hook (<NUM>);
"c". passing the loop of the elastic connector (<NUM>) around both the hook (<NUM>) and the frame (<NUM>);
"d". passing the loop through a through opening (<NUM>) at the edge of the trampoline jumping mat (<NUM>); and
"e". pulling the loop back to the clip (<NUM>) and over a protrusion (<NUM>) formed in the clip (<NUM>).