WO2019093893A1

WO2019093893A1 - Underlayment for dampening a top floor

Info

Publication number: WO2019093893A1
Application number: PCT/NL2018/050750
Authority: WO
Inventors: Dizzy Soederhuizen; Eric SARELSE
Original assignee: Supersub Sportbases B.V.; Soederhuizen Global B.V.
Priority date: 2017-11-13
Filing date: 2018-11-12
Publication date: 2019-05-16
Also published as: NL2019898B1

Abstract

Underlayment (1) for dampening a top floor of a floor assembly comprising a grid of plate- shaped base members (40). Each pair of neighbouring base members is interconnected by a connector (50). The connector (50) bridges a gap in between the neighbouring base members. The connector (50) protrudes below the base members. The connector (50) is U-shaped to provide flexibility to the connector. Each U-shaped connector has a first and second U-leg respectively connected to one of the neighbouring base members. Each U-shaped connector has a bottom portion interconnecting the U-shaped legs. The bottom portion (56) forms a supporting surface of the underlayment (1). The U-shaped connector (50) forms a foot for carrying the base member (40), such that upon placement, the underlayment rests on the plurality of feet which are solely formed by the connectors (50).

Description

Title: Underlayment for dampening a top floor. The present invention relates to a resilient underlayment, in particular a resilient

underlayment panel, which underlayment serves to support a top floor, in particular a pedestrian top floor for supporting moving humans or animals. More in particular the invention relates to a sports floor underlayment for supporting sporting people or a cattle floor underlayment for supporting moving animals.

Particularly, such a sports floor underlayment has to comply to strict technical requirements. For example, a sports floor should provide substantially the same damping characteristic at all places on the floor. A damping of a first step should feel the same in a next step independent of a position on the floor. In another example, a ball bounce should be reproducible over a complete floor surface within small tolerances. A ball may not bounce substantially harder at a first location with respect to another location.

Further, the invention relates to a damping floor assembly including an underlayment and a top floor, wherein the floor assembly is resilient to provide a damping characteristic. In particular, the invention relates to a damping sports floor assembly including a sports floor underlayment.

US2015/036886 discloses a system for regulating temperature and moisture on a field made of artificial turf, while also absorbing an impact G-force from the field. The system uses adjacently joint panels positioned beneath the field. Panels are sufficiently resilient to absorb an impact. Panels can be stacked to obtain a desired shock characteristic of the field. The panels have sufficient thermal mass to transfer heat between an underlying fluid and the field. The temperature of the fluid regulates the temperature of the field, such that the field can be heated and cooled accordingly. An interior region of each panel is defined by tube channels. The tube channel carries a fluid tube through the joint panels. The fluid tube carries a fluid having a predetermined temperature. The heat transfers between the fluid and field through the plurality of panels. The temperature of the fluid can be adjusted to affect the temperature on the field. The panels have water exfiltration and infiltration holes to drain a moisture build-up from the field, and aeration channels for circulation. The panels can be cut to contour or a length or width of the panel can be changed as each installation site dictates. US2009/0246418 disclose similar panels for artificial turf substrate which are made of a foam material and include an interlocking tab-and-notch structure.

The disclosed panels include several drawbacks. A first drawback is that a shock absorbance characteristic of the panels is rather rough and not accurately tuned to a particular use of a floor. A further drawback is that an installation of such panels is labour-intensive.

US4.054.987 discloses a recreational surface such as a tennis court surface which is constructed by interlocking together a sufficient number of square sheets. The court surface is assembled on a base or supporting surface of bitumine or concrete. The square sheets are thermoplastic sheets having a plurality of support legs at a lower side. The sheets are provided with connections which are arranged in between gratings. The connections are elastic and allow horizontal movements between gratings when the sheet is subjected to expansion or contraction due to thermal changes.

US8.668.403 discloses an impact absorbing underlayment panel having an impact absorbing structure configured to underlie a playground area. The panels have deformable projections which are regularly distributed at a bottom side of the panel. The deformable projections compress in a plurality of stages such that a load absorbing gradient is provided in response to an applied force. Each panel is solid and includes drainage holes and a grid of drainage channels to permit water to flow from a top surface of the panel through the drain holes and into the ground or other substrate below the panel.

EP2.480.722B1 discloses a damping floor including a composite structure of a textile underlayer and a flexible support structure which rests on the underlayer for supporting a covering, for example a synthetic grass. The support structure is attached to the underlayer. The support structure provides a damping characteristic to the covering and at the same time provides a solution to obtain a proper drainage. It is said that a problem of accumulating water between a covering and a rubbery under layer which might create puddles is minimised.

The support structure is a plate which has alternating crests and valleys in sinuous succession along a deformation direction X. The support structure comprises main ribs which extend in a transversal direction Y which is orthogonal to the deformation direction X.

The support structure comprises a plurality of tabs which project from the ribs. The tab comprises an overhanging portion which in a non-deformed configuration of the support structure - in other words when said structure is not being walked on - is vertically distanced from a substrate or underlayer. An embodiment is illustrated in which the support structure comprises ribs laying on the underlayer. Overhanging portions project from a rib and are arched in a concave manner towards the underlayer as far as a subsequent rib.

A drawback of this disclosed damping floor is that its damping characteristic is not consistent in any direction at all positions on the field.

The general object of the present invention is to at least partially eliminate the above mentioned drawbacks and/or to provide a useable alternative. It is an object of the invention to provide a resilient underlayment which complies to technical requirements which are predetermined for a damping floor.

More specific, it is an object of the invention to provide a resilient underlayment which provides an improved shock absorbance which is tuned to a particular use of a floor. In particular, the invention aims to provide a sports floor underlayment which provides a substantially constant damping characteristic at any place and in any direction on the sports floor. In particular, it is an object of the invention to provide an underlayment which features a climate control of the top floor. More in particular, it is an object to provide a shock absorbing underlayment which is user-friendly to install.

According to the invention, this object is achieved by an underlayment according to claim 1.

According to the invention, a resilient underlayment is provided for dampening a top floor of a floor assembly.

The resilient underlayment provides a damping characteristic which is adapted to loads originating from movements of walking or running activities on the top floor. The top floor may be a sports field, like a hockey or soccer field including an artificial turf top layer. In another example, the top floor may be arranged as a cattle floor for keeping a livestock. The top floor is arranged to carry moving people or animals, e.g. a sports floor. The top floor can also be called a pedestrian top floor for carrying living creatures.

The underlayment comprises a grid of plate-shaped base members. Each base member comprises a bottom side and a top side. The top side defines an imaginary plane, also called a horizontal plane, which plane extends in an X and Y direction. A normal direction of the horizontal plane is indicated by a Z-direction. The top side of a base member is arranged to support an upper layer of the floor assembly. Each base member comprises an outer circumferential side wall. The outer circumferential side wall includes in the X-direction at least a first side wall and a second side wall which second side wall is positioned opposite the first side wall. The outer circumferential side wall includes in the Y-direction at least a third side wall and a fourth side wall which third side wall is positioned opposite the fourth side wall.

In both the X-direction and the Y-direction, pairs of neighbouring base members are interconnected by at least one connector. A gap is provided in between the pair of neighbouring base members, which gap is bridged by the flexible connector. The connector has a first connector end which is respectively connected to a first base member of the pair of base members and a second connector end which is connected to a second base member of the pair of neighbouring base members.

The connector is U-shaped. The U-shaped connector has an axis of revolution oriented in the X or Y direction. The U-shaped connector has a first U-leg formed by the first connector end and a second U-leg formed by the second connector end. The U-shaped connector has a bottom portion including an outer surface, also called a bottom outer surface. The outer surface is spaced at a distance, e.g. at least 1 mm, from the bottom side of the base member. The outer surface forms a supporting surface of the underlayment. The connector is protruding below the base member bottom side to form a sole support for carrying the base member. Each connector forms a foot of a base member. Upon placement, the underlayment rests on its feet solely formed by the U-shaped connectors. Each base member is only supported by the connectors at the side wall when the underlayment is placed on a planar base.

The underlayment according to the invention may provide several advantages which will be described below.

A main advantage of the underlayment according to the invention is that the underlayment may provide a damping characteristic to a floor assembly which is tuned to predetermined technical requirements by the configuration of the connectors. The flexibility of the

underlayment is mainly determined by the U-shaped connectors protruding below the base members. The damping characteristic of the total floor assembly is largely determined by the flexibility of the underlayment. Herewith, the optimal configuration of the underlayment is a major factor in the technical performance of the floor assembly. The connectors interconnect the base members but at the same time provide a plurality of feet to the underlayment. The connectors space the base members at a distance from an underground or intermediate under layer of the floor assembly. In other words, the base members are floating above an underground by the connectors. Feet are provided by the connectors at the outer circumferential side wall of each base member. No feet are provided directly beneath the bottom side of the base members. Due to the protruding connectors, the base members are movable with respect to each other. The base members of the underlayment will move with respect to each other when a load is applied on the top floor in Z-direction, but also in X and Y direction. Herewith, the movable base members provide a shock absorbance to an occurring load on a floor assembly.

A predetermined size of the base members may result in a predetermined amount of connectors which form the feet of the underlayment to determine a resulting flexibility of the underlayment and hence determine a damping characteristic of the floor assembly.

Preferably, each base member has a square shape. In particular, each base member has a size of at most 15cm, preferably a size of at most 10cm. Such a size provide sufficient feet to provide a substantially constant damping characteristic at any place of the underlayment.

The U-shape of the connectors provide a flexibility in X-Y direction, but also in Z-direction. When carrying a load, the U-legs may flex away or towards each other and may slightly bend to provide a damping in both a horizontal and vertical direction. The size of the U-shaped connectors may be tuned to specific circumstances. Thicker connectors may for example provide a more rigid floor, a higher and/ or wider U-shape may for example provide more horizontal flexibility. The U-shape of the connector can be tuned to a desired damping characteristic. Preferably, the U-shape has a constant thickness extending from the first connector end along the first U-leg, along a U-bridge portion, along the second U-leg to the second connector end, to allow an accurate tuning to a predetermined damping

characteristic. In particular, the constant thickness of the U-shaped connector is at most 3mm, more in particular at most 2mm. Advantageously, the U-shape of the connector may contribute to an accurately predefined flexibility to the underlayment. A rigidity of the connector can be accurately calculated in a design phase of the underlayment, such that the flexibility of the underlayment can be accurately adapted to given requirements counting for a particular application. Herewith, the flexibility of the underlayment can be adapted to technical requirements valid for a sports field or can be adapted to different technical requirements valid for keeping a livestock at a cattle floor assembly.

In an embodiment of the underlayment according to the invention, the U-shaped connector has a straight bottom portion. The straight bottom portion provides a substantially rectangular supporting surface which contributes to a higher wear resistance. In particular, the straight bottom portion extends in between the U-legs about a distance of at least 2mm, preferably about at least 4mm. Advantageously, a more durable underlayment may be provided by the straight bottom portions of the U-shape when the underlayment is placed on an abrasive underground like a concrete underground .

In an alternative embodiment of the underlayment according to the invention, , the U-shaped connector has a bottom portion which is arcuate. The bottom portion extends along an arc curve. The U-legs may also be arcuate and may extend along a same axis of revolution of the arc curve. The arcuate connector has an axis of revolution oriented in X or Y direction. Endpoints of the curve of the connector are positioned at the side walls of the respective neighbouring base members. The outer surface of the bottom portion is downwardly directed and forms the supporting surface of the underlayment. The arcuate bottom portion may serve to receive a line element, e.g. a liquid conduit or electric cable.

In a further embodiment of the underlayment according to the invention, the U-shaped connector in between two neighbouring base members is arcuate over its whole length. The U-legs may also be arcuate, such that substantially the whole connector is arcuate. The arcuate connector may include a smooth, irregular or an undulated arc curve. Preferably, the arcuate connector may include a segment of a circle, a circular arc. The arcuate connector may form a lower half of a circle. In particular, the arcuate connector may include an inner arc radius of preferably at least 3 mm and at most 8 mm. Advantageously, the connector may be arranged to receive a line element, like a liquid conduit or electrical wire, to feature e.g. a climate control.

In an embodiment of the underlayment according to the invention, a pair of two neighbouring base members is interconnected by only a single connector. Preferably, the single connector is positioned at a middle region of a side wall of each base member. Advantageously, in comparison with a plurality of connectors at a side wall of each base member, a presence of a single connector may increase a flexibility of the underlayment. Alternatively, two connectors may be provided at a corner region of the side wall of each base member to reduce a flexibility of the underlayment. A selected amount of connectors in between two neighbouring base members may advantageously contribute to an accurate adaption of the total flexibility of the underlayment to particular technical requirements of a floor assembly.

In an embodiment of the underlayment according to the invention, each base member has a rectangular, in particular square, shape. The rectangular shape of the base member simplifies a configuration of the underlayment. The base member has a circumferential side wall including a first, second, third and fourth side wall. The base member may have sharp or chamfered corners.

In an embodiment of the underlayment according to the invention, each base member has an open structure. The open structure allows a through flow from a top side to a bottom side of the underlayment. In particular, the structure is open for at least 50%, more in particular at least 80%. In contrast to a solid structure which is closed, e.g. a structure of a panel of a foamed material, an open structure means that the underlayment is open by large openings e.g. provided a grid of ribs. The open structure of the base member allows an easy passage of fluids, in particular water, from a top side to a bottom side of the underlayment. The underlayment contributes to a proper drainage of the floor assembly. Advantageously, such an open underlayment is less vulnerable for floating upwards when a flow of water is supplied to the underlayment. Herewith, the underlayment is suitable to be used in a so called water- hockey field which is a sports playground conditioned by a sub-layer immersed in water.

In an embodiment of the underlayment according to the invention, each base member has at least one stopper at the base member bottom side. The stopper may be arranged to limit a downwardly directed movement of the base member. The stopper has a height relative to the base member bottom side which is lower than a height of the foot relative to the base member bottom side which foot is formed by the connector. Preferably, the height of the stopper is at least 1 mm, in particular at least 2mm, lower than the height of the foot formed by the connector. The base member is movable in downward direction until the stopper hits a counterpart, e.g. an underground or a lower layer of the floor assembly. Advantageously, the configuration of the stopper allows a further adaption of the underlayment to technical requirements of a particular floor assembly. The presence of a stopper limits a flexibility of the underlayment. The stopper may provide an additional stage to a damping characteristic for exceptional cases of heavy loads in comparison with a normal use, e.g. when a person is falling onto the floor in comparison with normal loads of a running impact. The stopper may prevent an overload of a connector in between two adjacent base members when for example a heavy maintenance machine rides over the top floor.

In an embodiment of the underlayment according to the invention, the stopper is positioned at a central region of each base member. Preferably, each base member is provided with only one single stopper. Preferably, the single stopper is a ring shaped. Preferably, the base member is square shape and the stopper is positioned at a midpoint of the square base member. The central positioned stopper may function for each connector at each side wall of the base member to a same amount which advantageously simplifies a configuration of the base member.

In an embodiment of the underlayment according to the invention, the stopper is integral with the base member. The base member including the stopper may be manufactured by injection moulding. Alternatively, the stopper may be a removable stopper to allow an exchange of a first type stopper with a second type stopper in dependency of given circumstances.

In an embodiment of the underlayment according to the invention, each base member is reinforced by at least one rib. Preferably, the at least one rib is provided at a base member bottom side. Each rib extends from a base member corner to the central region to increase a rigidity of the base member corner. Preferably, the at least one rib has a rib height relative to the base member bottom side which increases in a direction towards the central region. Especially, in an embodiment in which the at least one connector forming a carrying foot is positioned at a middle region of a side wall and in which the base member corner is freely extending, the at least one rib contributes to an equal response of the base member when a load is applied at either the base member corner or middle region of the side wall.

In an embodiment of the underlayment according to the invention, the base member topside comprises at least one projection for engaging an upper layer. Preferably, the at least one projection is a sharp projection which punctures into an upper layer being placed on top of the underlayment. Preferably, the base member topside is provided with a plurality of sharp projections. In particular, the sharp projection is relatively small sized, e.g. having a projection height of at most 2 mm. Advantageously, a large amount of a present base members which each includes at least one projection together provide a firm engagement of the

underlayment with an upper layer being placed on top of it. A load exerted on the upper layer is transmitted by the at least one projection to the underlayment in a direct manner which contributes to a dynamic response of the damping floor to the exerted load. In an embodiment of the underlayment according to the invention, the underlayment is mountable by an assembly of underlayment panels which are interconnectable by a snap- connection. Each underlayment panel includes a grid of base members. Outer positioned base members form together a circumferential panel outer side wall. Outer side walls of base members form a panel side wall which is provided with at least one of a male or female coupling member of a coupling element.

The mountable underlayment out of separate underlayment panels is advantageous, because such underlayment panels may be manufactured separately by injection moulding. The underlayment panels may be manufactured as a one piece item, where after the underlayment is obtained by snap fitting the underlayment panels.

In an embodiment of the underlayment according to the invention, the male or female coupling member is integral with a base member. The at least one coupling member can be manufactured as a one piece item with a base member by injection moulding.

Advantageously, no separate coupling elements are necessary for an assembly of the underlayment.

In an embodiment of the underlayment according to the invention, the male coupling member is shaped with in correspondence a connector. The male coupling member at the

circumferential panel side wall has a substantial equal shape as the connector positioned at an inner region of the panel. Preferably, a male coupling member comprises a U shape portion which is substantially equal to a U-shape of the connectors. As the connector, the male coupling member also function as a foot to the panel and contribute to the flexibility of the panel. Advantageously, the coupling members contribute to a uniform distribution of flexibility over the underlayment panel. Advantageously, a damping characteristic of the underlayment is uniformly distributed over the underlayment. Particular spots at the floor assembly having a different damping characteristic are prevented. In an embodiment of the underlayment according to the invention, the male coupling member has a free distal end which is provided with a tongue and wherein the tongue comprises a snap member for cooperating with a complementary snap member which is positioned inside an aperture of the female coupling member. By inserting the tongue of the male coupling member into the aperture of the female coupling member, the snap connection in between two neighbouring underlayment panels is obtained. In an embodiment of the underlayment according to the invention at least one of the male or female coupling members comprises an auxiliary snap member to provide an auxiliary snap connection in addition to a first snap connection. In the first snap connection, two

neighbouring underlayment panels are positioned at a first relative position with respect to each other. In the auxiliary snap connection, two neighbouring underlayment panels are positioned at a second relative position with respect to each other which differs from the first relative position. A total width or length of an underlayment can be varied by adapting a relative position of one or more underlayment panels. The total width or length of the underlayment can be adapted to a total available width or length for installation of the floor assembly. The at least two possible snap connections in between two neighbouring underlayment panels allows an adaption of a total size of an underlayment to an available area for installation. No cutting operations are necessary after a placement of the

underlayment which advantageously prevents waste material and reduces operational steps in installing a floor assembly.

Further, the invention relates to a damping floor assembly comprising an underlayment according to the invention. The damping floor assembly comprises a top floor, in particular a pedestrian top floor, for supporting moving humans or animals. In particular, the invention relates to a sports playground, e.g. a field hockey or running athletic playground.

In an embodiment of the damping floor assembly according to the invention, the floor assembly comprises a top floor which is arranged as a sports field. In particular, the top floor comprises a layer of artificial turf. Advantageously, the underlayment provides a required shock absorbance and damping characteristic to the sports field.

In an embodiment of the damping floor assembly according to the invention, the floor assembly comprises a top floor which is arranged as a cattle floor. The cattle floor is arranged for keeping livestock, like cows. Advantageously, the underlayment provides a damping characteristic to the floor assembly which is comfortable for animals walking or resting on top of the floor assembly.

In an embodiment of the damping floor assembly according to the invention, the damping floor assembly comprises at least one line element, like fluid conduits or electric wires, for conditioning the floor assembly. The floor assembly may comprise at least one line element to feature a climate control of the floor assembly. In particular, the underlayment comprises plurality of U-shaped connectors which are configured for receiving the line element. A plurality of U-shape connectors is aligned with each other. In particular, the U-shaped connectors may provide a receiving opening of at least 5 mm and at most 12 mm at the top side of the underlayment which allows an introduction of the line element into the U-shaped connectors. Further, the invention relates to a method for installing a floor assembly, in particular a sports playground, comprising the steps of providing an underlayment according to the invention; placing interconnected underlayment panels on an underground or a lower layer of the floor assembly; sizing the placed underlayment in correspondence with a predetermined floor area by moving neighbouring underlayment panels relative to each other by transforming a coupling provided by coupling elements from a first snap position to a second snap position or vice versa.

The invention will be explained in more detail with reference to the appended drawings. The drawings show a practical embodiment according to the invention, which may not be interpreted as limiting the scope of the invention. Specific features may also be considered apart from the shown embodiment and may be taken into account in a broader context as a delimiting feature, not only for the shown embodiment but as a common feature for all embodiments falling within the scope of the appended claims, in which:

Fig. 1A shows a perspective view on a top side of an underlayment panel according to the invention including a line element held by aligned connectors;

Fig. 1 B shows a top view of the underlayment panel as shown in Fig. 1 A;

Fig. 1 C shows in an enlarged view a base member of the underlayment panel;

Fig. 1 D shows a side view of Fig. 1 C;

Fig. 2A shows a perspective view focussing on a corner of the underlayment panel of Fig. 1A;

Fig. 2B shows an enlarged side view focussing on a side wall of the underlayment panel as shown in Fig. 1A;

Fig. 3A shows a cross sectional view of engaging male and female coupling members of a coupling element in between two neighbouring underlayment panels in which the coupling members are positioned in a first snap position;

Fig. 3B shows the coupling members of fig. 3A in a second snap position;

Fig. 4A shows a top view of a second embodiment of an underlayment panel according to the invention; Fig. 4B shows a perspective view focusing on a corner of the underlayment panel of fig. 4A;

Fig. 4C shows an enlarged view of the corner of Fig. 4B;

Fig. 4D shows a bottom view of the underlayment panel of Fig. 4A;

Fig. 4E shows a perspective view focusing on a corner of the underlayment panel of

Fig. 4D;

Fig. 4F shows an enlarged view of the corner of Fig. 4E; and

Fig. 4G shows a side view of the underlayment panel of Fig. 4A.

Identical reference signs are used in the drawings to indicate identical or functionally similar components.

To facilitate comprehension of the description and of the claims the words vertical, horizontal, longitudinal, cross-sectional - with reference to the gravity and to the coordinate system X,Y, Z shown in the drawings - are used in a non-limiting way.

A coordinate system including an X-, Y-, Z-axis is shown in the figures. The Z-axis defines a height or vertical direction. The X- and Y-axis define a horizontal plane. The X- and Z axis define a XZ-plane which is a vertical plane in a length direction of an underlayment panel. The Y- and Z-axis define a YZ-plane which is a vertical plane in width direction of an underlayment panel.

Fig. 1A shows in a perspective view an underlayment panel 10 according to the invention. An underlayment can be assembled by interconnecting a plurality of such underlayment panels 10. The underlayment panel 10 has a top side 11 for supporting an upper layer of a floor assembly. The top side of the underlayment panel defines an imaginary plane which extends in a horizontal plane in an X and Y direction. The underlayment panel 10 has an open structure. The open structure is provided by a rib structure. Seen from above, a large surface area of the underlayment is open. At least 50% of the surface area, in particular at least 80% of the surface area is open.

The underlayment panel 10 is a one piece item. The underlayment panel 10 may be manufactured by injection moulding. Further, Fig. 1 A shows a line member 20 which is introduced in a gap at the top side 11 of the underlayment panel. The line member 20 is a tube which is arranged for conducting a liquid through the underlayment e.g. for defrosting the floor assembly. The underlayment panel 10 has a bottom side 12. The underlayment panel 10 has a panel outer circumferential wall which is provided with a plurality of male and female coupling members 18, 19. The coupling members 18, 19 form in assembly a coupling element 17 for interconnecting neighbouring underlayment panels. Each underlayment panel 10 comprises a grid of interconnected base members 40, as illustrated in a Fig. 1 B. Here, each base member 40 has a rectangular shape, in particular a square shape.

As illustrated in Fig. 1 D which is an enlarged top view of Fig. 1 B, the base member 40 has a base member top side 41. As illustrated in a side view in Fig. 1 D, the base member 40 has a base member bottom side 42.

The base member 40 has an outer circumferential side wall 43. The circumferential side wall 43 includes in the X-direction a first side wall 43.1 which is positioned opposite a second side wall 43.2, and in the Y-direction a third side wall 43.3 which is positioned opposite a fourth side wall 43.4. Each adjoining side walls 43.1 , 43.3; 43.2, 43.4 from a base member corner 44. The first, second, third and fourth side wall are provided with a connector 50.

The base members 40 of the underlayment panel 10 are interconnected by connectors 50 which are flexible. The connectors 50 protrude in a downwards direction below the base member bottom side 42 and form a plurality of so-called feet of the underlayment panel 10. Herewith, the underlayment panel 10 is standing on the connectors 50 and the base members 40 are floating with respect to a planar base, which may be a ground surface or an intermediate lower layer of the floor assembly.

Each connector 50 include a connector body 500 which bridges a gap 'g' in between two neighbouring base members 40. The connector body 500 has a first connector end 53 which is fixed to a first base member and a second connector end 54 which is fixed to a second base member neighbouring the first base member. Both ends of the connector body 500 are fixed to a respective base member 40 of the pair of base members. The connectors 50 are flexible to allow the base members 40 to move relative to each other. Due to the flexibility of the connectors 50, the base members 40 are somewhat movable in the horizontal and vertical plane. The base members 40 are allowed to tilt about a small angle. Herewith, the flexibility of the connectors 50 are a factor in a damping characteristic of a floor assembly. The flexibility of the connectors 50 determine a shock absorbance of the floor assembly. Flexible means here that a connector may deform under a load exerted by a human or animal on the floor assembly.

A shape and a dimensioning of each connector 50 determine a flexibility of the connector.

The flexible connector 50 is U-shaped. The U-shaped connector 50 has U-legs which are formed by the first and second connector ends 53, 54. The U-shape connector 50 has a U- bridge portion including a bottom portion. The U-shaped connector 50 has a U-bend which provides a flexibility to the connector 50. The U-shape connector 50 is open from above (at the top side 11 of the underlayment panel) which allows an introduction of the line element 20 is shown in fig. 1A and hereafter in fig. 2B.

Here in Fig. 1-3, each connector body 500 is arcuate along its whole length. The connector 50 has an inner surface 51 which is concave and an outer surface 52 which is convex. The concave inner surface 51 is exposed upwardly. The concave inner surface 51 forms a bottom of a channel for receiving a line element 20, like an electrical or a liquid conduit.

The convex outer surface 52 is exposed downwardly. As illustrated, the connector 50 may have a smooth cross-section in width direction. Here, the connector 50 has a circular cross- section including an inner radius IR. The connector 50 is arcuate and has an inner radius of at least 3 mm and at most 8 mm. Alternatively, the connector 50 may have an undulated cross-section.

Each connector 50 has a connector length 'cl' and a connector width 'cw'. The connector length is a dimension extending in parallel with a side wall of the base member 40. The connector length 'cl' of a connector may be constant or may be varying which means a decreasing or increasing length seen over an arc length of the connector. The connector width 'cw" determines a relative distance in between two neighbouring base members 40. The connector width 'cw' determines a dimension of the gap in between two neighbouring base members 40 in an unloaded condition. Each connector 50 has a connector height 'ch' which determines how far the connector 50 protrudes beyond the bottom side 42 of the base member 40. The connector height determines how far a base member bottom side 42 is spaced from a planar base under the underlayment panel.

A particular dimensioning of the connector length, width and height determines a

corresponding flexibility of the connector. Increasing a connector width may reduce a bend stiffness of a connector and may increase a flexibility of the underlayment panel. Increasing a connector length may increase a bend stiffness of a connector and may reduce a flexibility of the underlayment panel. Increasing a connector height may reduce a bend stiffness of a connector and may increase a flexibility of the underlayment panel. Hence, a flexibility of the underlayment can be accurately defined in designing the connectors. Herewith, a

predetermined flexibility of the connector determines a damping characteristic of the floor assembly.

As shown in fig. 1 B and 1 C, each pair of neighbouring base members in X- and Y-direction is connected by a single connector 50. The connector 50 is positioned in a middle region at the side walls 43 of the neighbouring base members 40.

Fig. 1 D further shows a stopper 60 which is positioned at the base member bottom side 42. The bottom side 42 is flat. The stopper 60 protrudes away from the bottom side. Here, the stopper 60 is formed by a ring shaped boss including a circumferential ring-wall. The stopper 60 is arranged for limiting a downwardly directed movement of the base member 40. When the base member 40 moves over a predetermined distance in a downwards direction along the Z-axis, the stopper 60 gets in an abutting engagement with an underlying counterpart, e.g. the underground or a lower layer of the floor assembly. The predetermined distance Ah is defined by a difference in between the connector height 'ch' and the stopper height 'sh'. The stopper 60 has a stopper height which is at least 1 mm smaller than the connector height. The stopper 60 may prevent a further movement of the base member 40 in the downwards direction or may increase a stiffness to provide a second stage in a damping characteristic to anticipate on more heavy loads than in a first stage.

Fig. 2A shows an enlarged perspective view of a corner of the underlayment panel 10 as shown in Fig. 1A. The underlayment panel 10 has a panel side wall 13 which is provided with a plurality of coupling elements 17. The panel side wall 13 is formed by outer side walls of outer positioned base members 40 of the underlayment panel 10. Each coupling element 17 is formed by a male coupling member 18 and a complementary shaped female coupling member 19. The coupling members 18, 19 are arranged to provide a snap connection. Here, the coupling members 18, 19 are arranged to provide a first and second connection. Here, instead of separate parts, the coupling members are integral with a base member.

The male coupling member 18 is U-shaped. The male coupling member 18 has a U shaped member body which is substantially equal in shape to the connector body 500 as described above. Herewith, the male coupling member 18 functions in the same manner as the connector 50.

The male coupling member 18 has a free distal end extending away from a side wall 43 of the base member 40. The male coupling member 18 has a tongue 180 at the free distal end, which tongue is configured to be received in a complementary aperture of the female coupling member 19. The tongue 180 is provided with a snap member 181 which is arranged to co-operate with a complementary snap member 191 of the female coupling member 19. Here, the snap member 181 is a ridge which extends transversally to a longitudinal direction of the coupling member 18. The complementary snap member 191 is formed by an exposed edge in the aperture of the female coupling member 19. In assembling the coupling element 17, the ridge of the male coupling member 18 is engaging onto the edge of the female coupling member 19 to establish a snap connection in between neighbouring underlayment panels 10.

Fig. 3A and Fig. 3B show the male and female coupling members 18, 19 in further detail. The first underlayment panel 10.1 is positioned aside the second underlayment panel 10.2. A first base member 40.1 of the first panel 10.1 is positioned aside a second base member 40.2 of the second panel 10.2. The first and second panel 10.1 , 10.2 are interconnected by the coupling element 17. In fig. 3A, the coupling element 17 is illustrated in a first snap position. In fig. 3B, the coupling element 17 is illustrated in a second snap position. In comparison the first and second snap position, the first and second panels are spaced at a larger distance from each other in the second snap position. In operation, when installing the underlayment, the coupling element 17 is movable from the second snap connection (as shown in fig. 3B) to the first snap position (as shown in fig. 3A) Fig. 4 shows in several views another embodiment of an underlayment panel 10 according to the invention. Identical reference signs are used to indicate the same or similar features as illustrated above in figures 1-3. Fig. 4A shows a top view of an underlayment panel and fig. 4D shows a corresponding bottom view. The underlayment panel 10 comprises a matrix of base members 40 which are positioned side-by-side. Here, the underlayment panel comprises ten arrays of base members 40. Here, each base member is square shaped having a size of at most 10cm. The base members 40 are interconnected in both the X and Y direction by connectors 50. Each pair of neighbouring base members 40 is interconnected by a single connector 50. The single connector 50 is positioned at a middle region of a side wall of each base member 40.

The underlayment panel has a circumferential panel side wall 13 which is formed by the side walls of the base members 40. The side wall 13 of the underlayment panel 10 is provided with coupling elements 17 for interconnecting side-by-side positioned underlayment panels 10.

Fig. 4B shows the underlayment panel 10 in a detailed view in perspective seen from above. In fig. 4B it is illustrated that the configuration of the coupling elements 17 is similar to the configuration of the connectors 50. The coupling element 17 comprises a coupling body 170 which has a same configuration as a connector body 500. Both the coupling and the connector body 170, 500 are U-shaped. The coupling and the connector body have the same dimensions. After connecting neighbouring underlayment panels, the coupling body 170 interconnects two neighbouring base members 40 of separate underlayment panels 10 and forms as such a connection 50 which forms a foot of the underlayment.

Fig. 4C shows an enlarged view of fig. 4B to illustrate the base member 40 in further detail. The base member 40 has a planar topside 11 for supporting an upper layer. The planar topside 11 is provided with a plurality of sharp projections 46, see also Fig. 4G. The sharp projections 46 are upwardly directed. The sharp projections 46 are arranged to puncture an upper layer, such that the upper layer is engaged to the underlayment panel. A load exerted on the upper layer and acting in a horizontal plane will be transmitted by the projections 46 to the base member 40 of the underlayment panel 10. Fig. 4C and 4F further show the coupling element 17 which is formed by a tongue 180 including a snap member 181 and an aperture 190 including a complementary snap member 191. The aperture 190 is configured to receive the tongue 180, wherein the snap members are arranged to obtain a locking engagement.

Fig. 4E and fig. 4F respectively correspond with fig. 4B and fig. 4C, wherein the base members 40 of the underlayment panel are now illustrated from below.

Fig. 4E show the plurality of connectors 50 in between each pair of base members 40.

Fig. 4E and fig. 4F further show a stopper 60. The stopper 60 protrudes away from a flat bottom side 42. The stopper 60 is a ring shaped. The stopper 60 has a circumferential stopper wall, which is here a circular wall. The stopper 60 is positioned at a central region of the base member 40. Here, the base member 40 is square and the stopper 60 is positioned at a midpoint of the base member 40. The stopper 60 has a stopper height which is lower than a height of the foot formed by the connector 50, such that the base member 40 is allowed to flex downwards when loaded. The stopper 60 has a stopper face which is arranged to contact a planner base on which the underlayment is placed in case that the base member is fully loaded. The stopper 60 may prevent a deformation of the base member and/or the connectors around the base member in case of an overload. The stopper face is recessed with at least one recess 61 to enable a relief of an inner space inside the stopper 60. The at least one recess 61 decreases a water flow resistance through the base member.

Each corner 44 of the base member 40 is reinforced by a rib 45. The rib 45 extends diagonally across the bottom side of the base member. The rib 45 extends from the base member corner 44 to the central region, in particular to the midpoint, of the base member 40. Apart from the ribs 40 and the at least one stopper 60, the bottom side of the base member 40 is flat. The rib protrudes away from the flat bottom side 42. The rib 45 has a rib height which increases in a direction from the base member corner 44 to the central region. The height of the rib 45 is lower than the height of the stopper 60.

As a further shown in fig. 4G, each connector 50 has a connector body 500 which bridges a gap in between two neighbouring base members 40. The connector body 500 has a connector body length which extends along a side wall of the base member 40. Here, the connector body 500 has a length of about 20 mm. The connector body 500 is U-shaped in cross-section. In its cross-section, the U-shaped connector body 500 has a constant thickness of at most 3mm, in particular at most 2mm. The U-shape is defined by a first and second U-leg 53, 54 and a bridge portion 55.

The connector body 500 has a connector body width defined by the spaced U-legs. A first connector end 53 is connected to a first base member 40 and a second connector end 54 is connected to a second base member 40. The first connector end 53 forms a first U-leg of the U-shaped connector 50. The second connector end 54 forms a second U-leg of the U- shaped connector 50. The U-shaped connector 50 has a bridge portion 55 which connects both U-legs. The bridge portion 55 includes a straight bottom portion 56. The straight bottom portion extends in width direction over at least 2 mm. The bridge portion 55 comprises curved bottom portions 57 which interconnect the straight bottom portion to the U-legs. Each curved bottom portions 57 has an inner radius of at least 1 mm.

It is noted that the term "comprising" (and grammatical variations thereof) is used in this specification in the inclusive sense of "having" or "including", and not in the exclusive sense of "consisting only of".

Features and aspects described for or in relation with a particular embodiment may be suitably combined with features and aspects of other embodiments, unless explicitly stated otherwise.

Although the invention has been disclosed with reference to particular embodiments, from reading this description those of skilled in the art might appreciate a change or modification that may be possible from a technical point of view but which still do not depart from the scope of the invention as described above and claimed hereafter.

It will be understood by those of skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. It is in particular possible to make modifications with respect to the illustrated embodiments which are provided as exemplary embodiments.

Modifications may be made within the teaching of the invention and without departing from the scope thereof to adapt a particular situation or material. Therefore, the invention is not limited to the particular embodiments disclosed and illustrated in the above detailed description, but that the invention will include all embodiments falling within the scope as described above and defined in the appended claims. Thus, the invention provides an underlayment for dampening a top floor of a floor assembly comprising a grid of plate-shaped base members. Each pair of neighbouring base members is interconnected by a connector. The connector bridges a gap in between the neighbouring base members. The connector protrudes below the base members. The connector is U- shaped to provide flexibility to the connector. Each U-shaped connector has a first and second U-leg respectively connected to one of the neighbouring base members. Each U- shaped connector has a bottom portion interconnecting the U-shaped legs. The bottom portion forms a supporting surface of the underlayment. The U-shaped connector forms a foot for carrying the base member, such that upon placement, the underlayment rests on the plurality of feet which are solely formed by the connectors.

List of reference signs:

X direction 42 base member bottom side

Y direction

Z direction 43 circumferential side wall

43.1 first side wall

1 underlayment 43.2 second side wall

43.3 third side wall

10 underlayment panel 43.4 fourth side wall

1 1 topside 44 base member corner

12 bottom side 45 rib

13 circumferential panel side wall 46 projection

17 coupling element 50 connector

18 male coupling member 500 connector body

180 tongue 51 inner concave surface

181 snap member 52 outer convex surface

53 first connector end

19 female coupling member 54 second connector end

190 aperture 55 bridge portion

191 complementary snap member 56 bottom portion

192 auxiliary snap member 57 curved portion

20 line element 60 stopper

61 stopper recess

40 base member ch connector height

41 base member topside cl connector length cw connector width sh stopper height Ah height difference

9 gap

IR inner radius

Claims

1. Underlayment (1 ) for dampening a top floor of a floor assembly comprising a grid of plate-shaped base members (40), wherein each base member (40) comprises:

- a bottom side (42) and a top side (41), wherein the top side defines an imaginary plane which plane extends in an X and Y direction and which top side is arranged to support an upper layer of the floor assembly; and

- an outer circumferential side wall (43) which includes

o in the X-direction at least a first side wall (43.1) and a second side wall (43.2) which second side wall is positioned opposite the first side wall; and

o in the Y-direction at least a third side wall (43.3) and a fourth side wall (43.4) which third side wall is positioned opposite the fourth side wall; wherein the grid comprises at least one pair of neighbouring base members (40) in both the X-direction and Y-direction of the grid in which each pair of neighbouring base members (40) is interconnected by at least one connector (50),

which connector (50) bridges a gap (g) in between the neighbouring base members (40); and

which connector (50) has a first connector end (53) which is connected to a first base member of the pair of base members and a second connector end (54) which is connected to a second base member of the pair of base members,

wherein the connector (50) is U-shaped to provide a flexibility to the connector, wherein the U-shaped connector (50) has an axis of revolution oriented in the X or Y direction, wherein the U-shaped connector (50) has a first U-leg formed by the first connector end (53) and a second U-leg formed by the second connector end (54), wherein the U-shaped connector (50) has a bottom portion which has an outer surface (52) which forms a supporting surface of the underlayment

, wherein the U-shaped connector (50) is protruding below the base member bottom side (42) to form a foot for carrying the base member (40), such that upon placement, the

underlayment rests on a plurality of feet which are solely formed by connectors (50).

2. Underlayment according to claim 1 , wherein the U-shaped connector (50) has a straight bottom portion (56).

3. Underlayment according to claim 1 , wherein the U-shaped connector (50) has a bottom portion which is arcuate and wherein, in particular, the connector comprises an inner concave surface (51) including an inner radius of at least 3 mm and at most 8 mm.

4. Underlayment according to any of the preceding claims, wherein a pair of two neighbouring base members (40) is interconnected by only a single connector (50), wherein, in particular, the single connector is positioned in a middle region of a side wall.

5. Underlayment according to any of the preceding claims, wherein the base member (40) has an open structure which open structure is in particular open for at least 50% of its top surface area.

6. Underlayment according to any of the preceding claims, wherein each base member (40) comprises at least one stopper (60) protruding from a bottom side (42) for limiting a downwardly directed movement of the base member (40).

7. Underlayment according to claim 6, wherein the at least one stopper (60) is positioned at a central region of the base member (40).

8. Underlayment according to claim 6 or 7, wherein each base member (40) is reinforced by at least one rib (45) which rib extends from a base member corner (44) to the central region.

9. Underlayment according to claim 8, wherein the at least one rib (45) is provided at a bottom side (42) of the base member (40).

10. Underlayment according to claim 8 or 9, wherein the at least one rib (45) has a rib height which increases in a direction towards the central region.

1 1. Underlayment according to any of the preceding claims, wherein the base member top side (41) comprises at least one projection (46) for engaging an upper layer.

12. Underlayment according to any of the preceding claims, wherein the underlayment (1) is mountable by assembling a plurality of underlayment panels (10) which are to be coupled to each other by a snap-coupling, wherein each underlayment panel includes a grid of base members (40) which are interconnected by connectors (50) and wherein outer side walls of the base members (40) form a panel side wall which panel side wall is provided with at least one of a male or female coupling member (18, 19) of a coupling element (17).

13. Underlayment according to claim 12, wherein the male or female coupling member (18, 19) is integral with the base member (40).

14. Underlayment according to any of the claims12 or 13, wherein the male coupling member (18) has a free distal end provided with a tongue (180) and wherein the female coupling member (19) provides an aperture for receiving the tongue (180) and wherein the tongue comprises a snap member for cooperating with a complementary snap member positioned inside the aperture of the female coupling member.

15. Underlayment according to claim 14, wherein the male coupling member (18) is shaped in correspondence with a connector (50), wherein the male coupling member (18) comprises a U-shaped portion which forms a foot for carrying the base member (40).

16. Underlayment according to any of the claims 12-15, wherein at least one of the male or female coupling members (18, 19) comprises an auxiliary snap member to provide an auxiliary snap connection at another relative position of neighbouring underlayment panels.

17. Underlayment according to any of the claims 12-16, wherein the underlayment panel (10) is manufactured by injection moulding.

18. Damping floor assembly, in particular a sports playground, comprising an underlayment according to any of the claims 1 - 17.

19. Damping floor assembly according to claim 18, wherein the underlayment comprises a plurality of U-shaped connectors (50) which are open at a top side (11) of the underlayment, wherein the connectors are aligned with each other and a line element (20) which is receivable within the connectors (50).

20. Method for installing a floor assembly comprising the steps of:

- providing an underlayment according to any of the claims 1- 17;

- placing interconnected underlayment panels on an underground or lower layer of a floor assembly;

- sizing the placed underlayment in correspondence with a predetermined floor area by moving neighbouring underlayment panels relative to each other by transforming a coupling provided by coupling elements (17) from a first snap position to a second snap position or vice versa.