GB2413490A

GB2413490A - A device for holding a dust sheet in position

Info

Publication number: GB2413490A
Application number: GB0409475A
Authority: GB
Inventors: Dennis Davy Anderson
Original assignee: Dda Innovation & Design Ltd
Current assignee: Dda Innovation & Design Ltd
Priority date: 2004-04-28
Filing date: 2004-04-28
Publication date: 2005-11-02
Also published as: GB0409475D0

Abstract

A device for holding a dust sheet in position comprises a generally I or T-shaped nylon plate having projections 110 112 88 90 92 94 102 103 at one end and a pin 86 which projects at right angles to the plate at the other. In use, a dust sheet 182 is arranged adjacent a wall and a gripper rod 176 and a projection 158 is inserted through the sheet and into the carpet so the device is at an acute angle to the carpet. In this position the device is pivoted toward the gripper rod 176 and the pin 86 passes through the carpet. The end of the pin is then laterally flexed by the gripper rod which simultaneously causes the plate to flex. The flexing of both pin and plate serve to wedge the plate against the wall and releasably anchors the plate and dust sheet in position. Branches 68 70 76 78 inhibit rotational pivoting in the plane of the plate of the device when fitted.

Description

. - - . - / 241 3490 - 1 - A Device for Holding a Dust Sheet in

Position The present invention relates to a device for holding a dust sheet in position over a floor covering, to a kit of such devices, and to a method of manufacturing the device.

Many interior floors are covered with carpet that is relatively expensive to buy and fit. When decorating the interior of a building or carrying out building works it is common practice to lay "dust sheets" on the floor to protect the carpet against inter alla paint shavings when stripping old paint, accidental paint spills, specks of paint from rollers, and building debris and dirt.

Difficulty is encountered when attempting to cover and protect carpet with dust sheets, yet ensure safety for the workers working in room and users of the building. In particular, dust sheets come in a variety of materials, for example cotton and polythene sheets, and even old newspapers, and it is not easy to hold the dust sheets securely in position covering substantially all of the carpet during works. A person walking across the room can often trip on the loose dust sheets. At best this problem can cause inconvenience and expose part of the carpet, and at worst a fall and injury.

GB-A-2 290 993 relates to an adhesive bordered dust sheet having one edge coated with adhesive protected by a strip that can be removed prior to use. After removal of the strip, the adhesive part of the dust sheet is adhered to floor coverings to hold the dust sheet in position. It will be appreciated that in such an arrangement the adhesive will only be useable one or a few times. It will quickly become covered in dirt, carpet fibres, etc. and thereafter be ineffective.

It is an aim of the present invention to provide a device for holding dust sheets and the like in position over a floor covering on a floor.

I.*: .. ë - 2- According to the present invention there is provided a device for holding a dust sheet in position over a floor covering, which device comprises first engaging means for directly or indirectly engaging or co-operating with a gripper rod under the floor covering whereby in use the device and dust sheet may be held substantially in position relative to the floor covering. The device itself may act directly on a dust sheet to hold it in position, for example under a compressive force between the device and the floor covering; or may be provided with other means for gripping the dust sheet, for example a hand operated clamp or clip that can be operated once the device has been secured on the floor.

Preferably, in use the first engaging means provides a wedging of a part of the device between a wall and directly or indirectly said gripper rod. This is particularly useful as the device can be operated by hand without tools. In one embodiment, said wedging causes flexing of a flexing part of the device so as to apply a substantially continuous downward force to the dust sheet adjacent the wall.

Advantageously, said flexing part comprises said first engaging means. In one embodiment the first engaging means comprises one part at a proximal end of the device that moves relative to another part during the wedging of the device, the movement generating a restoring force on the one part tending to rotate a distal end of the device downwardly onto the dust sheet.

Preferably, said flexing part comprises a body of said device.

Advantageously, said first engaging means comprises an engaging part for engaging a wall adjacent said floor covering, whereby in use upward movement of the device away from the floor covering is inhibited. Such engaging part may also serve to assist the wedging effect by e i.: I.. . e... - 3-

inhibiting further movement of the device toward the wall.

Preferably, the device further comprises inhibiting means for inhibiting rotation of the device in a plane substantially parallel to a plane defined by the floor covering. This helps to inhibit premature release of the device through repeated by movement of the dust sheet caused by footsteps for example.

Advantageously, in use said inhibiting means abut part of a wall adjacent said floor covering. In one embodiment said inhibiting means provide points of abutment that are at least approximately 35mm apart in use.

Preferably, said first engaging means is such that in use it penetrates said carpet and passes into a gap defined between said gripper rod and a wall adjacent the floor covering.

Advantageously, said first engagement means is such that, in use, said floor covering can be penetrated at an oblique angle, whereby the position of the gripper rod does not need to be determined prior to use of the device. Thus the device is quick and easy to use, without requiring accurate pre-positioning. In one embodiment the device is such that, when resting on a dust sheet before use, one end of the device is held at a higher position than the other end of the device to provide said oblique angle.

Preferably, said first engagement means is such that in use it penetrates said floor covering before engaging part of a wall, further penetration of the first engagement means into the carpet causing the device to be wedged between the wall and directly or indirectly said gripper rod.

Advantageously, said first engagement means comprises a part that is positioned a distance from a A. c.: ë . ee. - 4-

first end of the device that is less than the distance between a wall and the gripper rod during penetration of the floor covering. This helps to ensure that the part misses the gripper rod. (14) In one embodiment the distance is between 6 and lOmm.

Preferably, said first engaging means comprises at least one pin for penetrating said floor covering in use.

In one embodiment the longitudinal axis of the pin is substantially perpendicular to a body of the device. This helps to ensure that the wedging effect takes place during penetration of the floor covering.

Advantageously, said device comprises means for resisting removal of the pin from a floor covering into which it is inserted or driven. In one embodiment said means for resisting comprises one or more grooves on a shank of the pin.

Preferably, said pin has an exposed length that is longer than the thickness of said floor covering. The flexing of the pin in use is normally enough to ensure that the pin does not encounter the floor underneath before the device is securely located. Preferably, said pin has an exposed length of approximately 18-25mm.

Advantageously, the device further comprises gripping means for inhibiting movement of the dust sheet relative the device in use.

Preferably, said gripping means comprises a projection that is brought into contact with said dust sheet during use. In one embodiment the gripping means projects downwardly of a body of the device in use. The projection may be such that movement of the dust sheet relative to the projection results in substantially no upward force on the device.

Advantageously, said projection is adapted to resist movement of said dust sheet in at least one direction.

Preferably, the device further comprises a cross . .: .- .. .. ... 5-

member supporting said gripping means.

Advantageously, said cross member has a width that is wider than a body portion of the device.

Preferably, said gripping means are spaced across said cross member, whereby twisting of the device substantially parallel to a plane defined by said floor covering is inhibited.

Advantageously, the device further comprises a substantially flat surface that faces upwardly during use. This helps to that people working nearby do not trip over the device for example. "Substantially flat" may include small ridges, undulations, projections, etc. provided they would not present a hazard to a user when in use.

Preferably, the device further comprises second engaging means for engaging a floor covering between the tread of a stair and the riser of the next stair up, whereby the device can hold dust sheets in position both on a floor and on stairs.

Advantageously, said second engaging means are provided at an end of the device opposite to said first engagement means.

Preferably, said second engaging means comprises a projection for insertion into a fold of the floor covering between said tread and said riser.

Advantageously, said projection comprises a curved spike having a point on or below a plane defined by the body of the device.

Preferably, said first engagement means in use can pass through said floor covering to engage said tread.

Advantageously, the device further comprises at least one projection for inhibiting movement of the dust sheet up or down the stairs during use.

Preferably, said at least one projection projects forwardly and downwardly relative to the device in use.

.e e. A.. ce. - 6-

Advantageously, said device further comprises means for inhibiting rotation of the device in a plane substantially parallel to a plane defined by the floor covering, whereby working loose of the device by the footsteps of users of the stairs is inhibited.

Preferably, said inhibiting means comprises a cross member for abutment with the floor covering at the join between the tread and the riser.

Advantageously, the device further comprises at least one hole or recess in a body portion of the device for releasable securing a protecting member to the device.

Preferably, the device comprises a material that provides elastic flexibility to a body of the device for accommodating said wedging function whilst providing a return spring force to assist holding said dust sheet in position. This flexibility may correspond to a flexural modulus of approximately 8 GPa.

Advantageously, said material comprises a plastics, a reinforced plastics or other material having a substantially equivalent flexibility to that mentioned above. In one embodiment the plastics material is an industrial grade of Nylon 66 30% glass fibre filled.

According to another aspect of the present invention there is provided a method of manufacturing a device as set out above, which method comprises the steps of forming a body portion and providing said body portion with said first engagement means.

Preferably, said forming step comprises the step of injection moulding said body portion.

Advantageously, the method further comprises the step of inserting said first engagement means into said body portion and curing said body portion.

The method may further comprise the step or steps of providing the device with any of the aforesaid features.

I..: .e ë... - 7-

According to another aspect of the present invention there is provided a kit for holding down dust sheets in a room, which kit comprises a plurality of devices as set out above.

Preferably, the kit further comprises a dust sheet for use with said plurality of devices.

Advantageously, the kit further comprises a protecting member for use with a device, that arrangement being such that, in use, the device can retain the protecting member in position over part of a tread of a flight of stairs.

Preferably, the kit further comprises a set of instructions for using each device substantially as herein described or substantially as shown in Fig. 10 and/or Fig. 11 of the accompanying drawings.

According to another aspect of the present invention there is provided a device for holding a dust sheet in position on stairs, which device comprises an engagement means for penetrating a floor covering and engaging a tread thereunder. Such a device may comprise any of the features set out above.

it; .... - 8-

For a better understanding of the present invention reference will now be made by way of example to the accompanying drawings, in which: Fig. 1 is a schematic plan view of a first embodiment of a device in accordance with the present invention; Fig. 2 is a schematic end view of the device of Fig. 1: Fig. 3 is a schematic side view of the device of Fig. 1, with some parts shown in detailed exploded views; Fig. 4 is a schematic plan view of a second embodiment of a device in accordance with the present invention; Fig. 5 is a schematic side view of the device of Fig. 4; Fig. 6 is a schematic plan view of a third embodiment of a device in accordance with the present invention; Fig. 7 is a schematic side view of the device of Fig. 6; Fig. 8 is a schematic side view, partly in cross section, of a device in accordance with the present invention in a first position before movement to a second position for holding a dust sheet; 25Fig. 9 is a schematic side view of the device of Fig. 8 in the second position after emplacement; Fig. 10 shows schematically the stages of fitting and removing a device in accordance with the present invention in a floor fixing application; and 30Fig. 11 shows schematically the stages of fitting to the tread of a stair a device in accordance with the present invention.

Referring to Figs. 1, 2 and 3 a device generally identified by reference numeral 10 comprises a body 12 approximately of "T" shape that is made wholly from Nylon i:.: I-; ... 9-

66 A6601 30% Glass Fibre Filled Industrial Black (available from Polymers Direct Ltd. Warwick, United Kingdom www. polymersdirect.com). The properties of this material are as follows: l TEST TEST METHOD PROPERTY METHOD UNITS 30%

ISO EQUIV

l ASTM Physical Specific gravity D792 ISO 1183 kg/m3 1.36 Water Absorption D570 ISO 62 % 0.7 Mould shrinkage (flow) ISO 2577 % 0.3 Mechanical Tensile Strength D638 ISO 527 MPa 175 Elongation at break D638 ISO 527 % 3 Flexural D790 ISO 178 MPa 250 strength Flexural modulus D790 ISO 178 GPa 8 Notched Charpy Impact ISO 179/leA kJ/m2 60 Thermal Melting point ISO 3146 C 255 Deflection D648 ISO 75 C Temperature At 1.85MPa 245 At 0.46MPa 250 The device weighs about 0.018kg. A first end 14 of the body 12 has a substantially flat surface 16 of 21mm length extending between two edges 18, 20 disposed substantially perpendicularly thereto. The edges 18, 20 A.: A.. .

.e - 10 are substantially straight and parallel along the body 12 for about 54mm, after which they flare outwardly in a generally curved fashion to define a cross member 24 such that the device 10 resembles a "T" shape. A second end 26 of the body 12 is substantially flat and has rounded ends 30, 32 joining the flared part of each edge 18, 20 respectively. The body 12 has an overall length of about 103mm, a width of the upper part of the "T" is 150mm, and is of a uniform thickness of about 3.5mm. The body 12 has a cut-out 22 to reduce weight that extends along body 12 for 67mm and is of 12mm width. Each end of the cut-out 22 is rounded...DTD: The body 12 has a substantially flat upper surface 34, whilst a lower surface 36 is also substantially flat for its majority other than a number of projections. At the first end 14 of the body a metal pin 38 projects substantially perpendicularly to a plane defined thereby.

The longitudinal axis of the pin 38 crosses the longitudinal axis of the body 12 (i.e. of the upright of the "T" shape) at a point approximately 8. 5mm in from the edge 16. The pin 38 is 25mm long having a shank of 1.4mm maximum external diameter with the head part of the pin accommodated securely in the body 12, whilst the point of the pin is left free. 2.5mm of the head part of the pin 38 is within the body 12 whilst the remaining 22.5mm projects outwardly therefrom. The pin 38 is of the ring shank type i.e. it comprises a plurality of circumferential grooves along part of the length of its shank. Such pins are readily available in hardware

stores, for example.

Two projections 42, 44 are spaced along each side of the body 12 between the parallel part of the edges 18, 20 (i.e. the upright part of a "T" shape) spaced approximately one-third and two-thirds along the length of the body 12 respectively. Each projection 42, 44 (see I:.: A; ..

- 11 - detailed view in Fig. 3) is injection moulded as part of the body 12 and has three exposed substantially planar surfaces 46, 48, 50 such that the projection is of triangular cross section that gradually decreases in area to a point. The planar surfaces 46, 48, 50 approximately define an equilateral triangle where they meet the body 12. Two of the planar surfaces 46, 48 have a common edge and extend substantially perpendicularly to the lower surface 36 of the body 12 and at about 60 to each other.

The third planar surface 50 joins the remaining free edge of each planar surface 46, 48. Each projection 42, 44 is oriented on the body 12 such that the third planar surface 50 faces toward the second end 26 and is angled backwardly toward the first end 14 by an angle of approximately 120 to the plane of the body 12. The first and second planar surfaces 46, 48 are oriented substantially at 45 to the longitudinal axis of the body 12.

Spaced along the length of the cross member 26 is a plurality of projections 52. Each projection 52 is similar in dimensions and orientation to the projections 42, 44. A space 54 of 14mm width is provided between each projection 52.

How the device 10 is used will be described in conjunction with Figs. 6 and 7 below.

Referring to Figs. 4 and 5 a second embodiment of a device generally identified by reference numeral 60 comprises a body 62 resembling an "I" which body is made wholly from Nylon 66 30% glass fibre filled i.e. the same as that mentioned above. The device 60 weighs 0.018kg. A first end 64 of the body 62 has a substantially flat surface 66 of 60mm length, the ends of which are rounded and join edges 68, 70 that taper inwardly in a curved fashion to a central body portion of 25mm width. The edges 68, 70 are substantially straight and parallel . is: ....- c.. - 12

along the central body portion for about 50mm, after which they flare outwardly in a generally curved fashion to a width of 150mm over a distance of 24mm to define a cross member 72 such that the device 60 has a shape in plan view that resembles an "I". A second end 74 of the body 62 is substantially flat and has rounded ends 76, 78 joining the flared part of each edge 68, 70 respectively.

The body 62 has an overall length of about 103mm, a width of the second end 74 (i.e. the upper part of the "I") is 10150mm, and is of a uniform thickness of 3.5mm. A plurality of nine rectangular holes 80 is spaced along the length of the body 62 over a distance of 77mm. Each rectangular hole 80 is lOmm by 5mm and is separated by a portion of lOmm by 4mm by 2mm.

15The body 62 has a substantially flat upper surface 82 whilst a lower surface 84 is substantially flat for its majority other than a number of projections. At the first end 64 of the body 62 a metal pin 86 projects from and substantially perpendicularly to a plane defined by the lower surface 84. The longitudinal axis of the pin 86 crosses the longitudinal axis of the body 62 (i.e. of the upright of the "T" shape) at a point approximately 8.5mm in from the edge 66. The pin 86 is 25mm long having a shank of 1.4mm maximum external diameter with the head part of the pin accommodated securely in the body 62, whilst the point of the pin 86 is left free. 2.5mm of the head part of the pin 86 is within the body 62 whilst the remaining 22.5mm projects outwardly therefrom. The pin 86 is of the ring shank type i.e. it comprises a plurality of circumferential grooves along part of the length of its shank.

Four projections 88, 90, 92, 94 are spaced along the length of the cross member 64 on the lower surface 84 at and are each spaced 2mm in from the second end 74. Two projections 88, 90 are provided on one side of the cross of: . . - 13 member 72, and the other two projections 92, 94 are provided on the other side of the cross member. The outer projections 88, 94 are spaced 26mm in from the extremities of the cross member 72, with the remaining projections 90, 92 spaced inwardly by 22.5mm from the outer two projections 88, 94 respectively. Each projection 88, 90, 92, 94 is injection moulded as part of the body 62 and has three exposed substantially planar surfaces 96, 98, 100 such that each projection is of triangular cross section that gradually decreases in area to a point. The planar surfaces 96, 98, 100 approximately define an equilateral triangle where they meet the body 62. Two of the planar surfaces 96, 98 have a common edge of 6mm length and extend substantially perpendicularly to the lower surface 66 of the body 62 and at about 60 to each other. The third planar surface 100 joins the remaining free edge of each planar surface 92, 94, each having a length of 8mm. Each projection 88, 90, 92, 94 is oriented on the body 12 such that the third planar surface 100 faces toward the second end 66 and is angled backwardly toward the first end 64 by an angle of approximately 120 to a plane passing through the body 62. The first and second planar surfaces 96, 98 are oriented substantially at 45 to the longitudinal axis of the body 62.

Spaced along the length of the cross member 72 are two sets of projections 102, 103. Each set 102, 103 is separated in the middle of the cross member 72 by a distance of 32mm. Each projection 102 is similar to the projections 88, 90, 92, 94. However, each projection 102 is smaller than projections 88, 90, 92, 94 and is oriented on the flat face of the second end 74 to face forwardly of the body 62 such that a point 104 of each projection is positioned about lmm below the lower surface 84. The length of each projection 102 between the . cat::e . - 14 second end 74 and the point 104 is 5mm. An upper flat surface 106 of each projection 102 is angled at approximately 45 to the plane of the body 62 such that it does present a hazard when the device is in use. A space 108 of 3mm width is provided between each projection 102.

Two curved projections 110, 112 each of 20mm length are spaced between the two sets of projections 102, 103.

Each curved projection 110, 112 points forwardly of the body 62 (in the same sense as the projections 102) and comprises a substantially curved spike of tapering width and thickness. The width tapers from 8mm to a point 114 of about lmm width. The thickness tapers from about 4mm to about O.5mm at the point 114. Each point 114 is about 7mm below the upper surface 82.

How the device 60 is used will be described in conjunction with Figs. 6 and 7 below.

Referring to Figs. 6 and 7 a device generally identified by reference numeral 120 comprises a body 122 approximately of "T" shape which body is made wholly from Nylon 66 A6601 30% Glass Fibre Filled Industrial Black i. e. the same as that mentioned above. The device 120 weighs about 0.018kg. A first end 124 of the body 12 has a substantially curved surface 126 extending between two edges 128, 130. The edges 128, 130 are substantially straight and parallel along the body 122 for about 54mm, after which they flare outwardly in a generally curved fashion to define a cross member 134 such that the device resembles a "T" shape. A second end 136 of the body 12 is substantially flat and has rounded ends 138, 140 joining the flared part of each edge 128, 130 respectively. The body 122 has an overall length of about 103mm, a width of the upper part of the "T" is 150mm, and is of a uniform thickness of about 3.5mm. A plurality of nine rectangular holes 142 is spaced along the length of A: A. e.e - 15 the body 122 over a distance of 77mm. Each rectangular hole 142 is lOmm by 5mm and is separated by a portion of lOmm by 4mm by 2mm.

The body 122 has a substantially flat upper surface 144, whilst a lower surface 146 is also substantially flat for its majority other than a number of projections.

At the first end 124 of the body 122 a metal pin 148 projects substantially perpendicularly to a plane defined thereby. The longitudinal axis of the pin 148 crosses the longitudinal axis of the body 122 (i.e. of the upright of the "T" shape) at a point approximately 8.5mm in from the edge 16. The pin 148 is 25mm long having a shank of 1. 4mm maximum external diameter with the head part of the pin accommodated securely in the body 122, whilst the point of the pin is left free. 2.5mm of the head part of the pin 148 is within the body 122 whilst the remaining 22.5mm projects outwardly therefrom. The pin 148 is of the ring shank type i.e. it comprises a plurality of circumferential grooves along part of the length of its shank. Such pins are readily available in hardware

stores, for example.

Spaced along the length of the cross member 134 are two sets of projections 150, 152. Each set 150, 152 is separated in the middle of the cross member 134 by a distance of 32mm. Each projection 156 of the two sets is similar to the projections 88, 90, 92, 94 described above in conjunction with Figs. 4 and 5.

Two curved projections 158, 160 each of 20mm length are spaced between the two sets of projections 150, 152.

Each curved projection 158, 160 points forwardly of the body 122 (in the same sense as the projections 156) and comprises a substantially curved spike of tapering width and thickness. The width tapers from 8mm to a point 114 of about lmm width. The thickness tapers from about 4mm to about 0.5mm at the point 114. Each point 114 is about . . . . . :. .e : . ee. - 16

7mm below the upper surface 82.

The devices 10, 60 and 120 may be used as illustrated in Figs. 8 and 9. The use in Figs. 8 and 9 will be described with reference to the embodiment of the device in Figs. 4 and 5. However, the devices 10 and 120 operate by the same principles with equivalent parts performing equivalent functions.

Referring to Figs. 8, 9 and 10 the device 60 is shown adjacent a wall 170 and floor 172, ready for use in a first application. The floor 172 has a carpet 174 that is held in place on the floor by a gripper rod 176 (or "gripper strip" or "nail bar" as they are sometimes called) and that is supported by an underlay 178. In accordance with the usual practice of carpet layers, the gripper rod 176 is positioned next to the wall 170 on the floor 172 to define a gap 179 that is less than the thickness of the carpet (usually about two-thirds of the thickness). Carpets with a backing (not shown) have thicknesses between about 8-20mm, although greater and lesser thicknesses are known. The gap 179 is frequently between 6-12mm with 8-lOmm being most frequent. During laying, once the carpet 172 has been tensioned between the gripper rods around the room, the edge 180 of the carpet is forced into the gap with a bolster to provide a neat finish. Since the carpet 172 is thicker than the width of the gap 179, that part which is forced into the gap 179 is compressed by the fitting process and held in place by friction fit (sometimes the end of the carpet 172 is folded back on itself and then compressed into the gap 179). Usually the length of this part of the carpet is approximately twice the length of the gap 179, typically 16-2Omm.

When the carpet 172 requires protection during building works, decorating, etc. a dust sheet(s) 182 is frequently laid loosely over the carpet. Dust sheets . . . ee. :. ë : . A. - 17 frequently comprise natural materials such as cotton, or plastic materials such as polythene, that provide a protective layer over the carpet but which can be folded and stored compactly when not required. Most often the dust sheet 182 is simply thrown roughly into position on the carpet and left there until no longer required. Such methodology leaves the dust sheet insecurely positioned during this time, possibly presenting a hazard should it move out of position, or at least leaving the carpet exposed to dust, paint, etc. which is undesirable.

The device 60 enables the dust sheet 182 to be securely held in position for the desired length of time.

The dust sheet is positioned over the carpet 172 with one edge adjacent the wall 170 (or skirting board). The device 60 is brought up to the wall 170 with the first end 64 having the pin 86 nearest to the wall. The flat surface 66 is brought substantially parallel with the wall 170 with theweight of the body resting on the dust sheet 182 on the point of the pin 86 and on the two projections 110, 112. Since the point of the pin 86 is further (in perpendicular distance) from the lower surface 84 than the points of projections 110, 112, the body 62 rests at an angle of about 1015 (ideally about 13 ) to the carpet 174 with the first end 64 being higher than the second end 72. Thus the pin 86 points downwardly and inwardly at an oblique angle (of the same size i.e. 10-15 ) toward the wall 170 with its point substantially above the inner edge of the gripper rod 176.

A user (not shown) presses the device 60 into the carpet 174 at a point on the upper surface 82 above the pin 86. The pin 86 penetrates the dust sheet 182 and the carpet 174 at this oblique angle and as the pin moves into carpet its point moves away from the gripper rod into the gap 179 (filled by the carpet), and the flat edge 66 of the device moves toward the wall 170 (or . . . ë :- ë.: . A. skirting board). Further movement of the device 60 brings the flat edge 66 into contact with the wall 170. After this happens, further downward movement causes (1) the pin 86 to flex slightly and (2) the body 62 to flex slightly. The flexing of the pin 86 is substantially in the vertical plane and the point of the pin 86 is displaced from its equilibrium position toward a plane containing the flat edge 66 as shown in Fig. 9. It is to be noted that the flexing shown in Fig. 9 is greatly exaggerated for the purposes of illustration and understanding.

The flexing of the body 62 is such that the upper surface 82 becomes slightly concave. Due to the flexural modulus of the Nylon material (mentioned above) from which the body 62 is made, this flexing is quite small and may not be perceptible by eye. Thus, the movement of the body during the flexing remains within the elastic limit of the body 62. However, the body 62 is not brittle so that it resists being broken if trodden on by a user, for example. It is to be noted that the value of the flexural modulus given in the table above may not be exactly that of the body 62 since the table provides properties of the material for a specified test piece.

The flexing (of both the pin 86 and body 62) occurs because the flat edge 66 cannot move any further toward the wall whilst the angle of penetration by the pin 86 tries to draw the device 60 toward the wall such that it is effectively "wedged" in position. The wedging effect results from contact between the flat edge 66 and the wall 170, and between the pin 86 and the carpet 174 (and thereby indirectly the gripper rod 176). Movement of the pin 86 back toward its equilibrium position is restrained by the portion of the carpet in the gap 179 and ultimately by the gripper rod 176. Depending on the exact position of the gripper rod 176, the point of entry in . ë :. :. ...: . .e.. - 19

the carpet of the pin 86 and the angle of the pin to the vertical, the pin may or may not be in contact with the upper inner corner of the gripper rod 176. The applicant has found that the ring shank nature of the pin 86 is particularly effective at gripping the carpet 172. Whilst ordinary smooth shank pins work well for many carpets, the applicant has found that they are liable to slip out from thicker carpets. The provision of the ring shank has solved this problem.

10The wedging and flexing effects leave the device 60 at slight downward angle to the horizontal as shown in Fig. 9 such that the second end 72 is lower than the first end 64. In this way the wedging and flexing causes the second end 72 of the device to apply downward 15pressure onto the dust sheet 182 and carpet 174. When properly positioned to take full advantage of the wedging and flexing effects, the curved projections 158, 160 and the projections 88, 90, 92, 94 are pressed into the dust sheet 182 and carpet 174. Since the device 60 has an upper surface 82 that is substantially flat, it does not present a hazard to people working in the room.

The downward pressure helps to hold the dust sheet 182 in position. In particular, when people walk over a dust sheet 182 that is not held in position by a device 60 it is caused to move gradually away from the wall.

Furthermore the applicant has identified a particular problem with securing dust sheets for any useful length of time: footsteps tend to pull the dust sheet in the plane of the carpet. Because each footstep is relatively localized, such forces are not always perpendicular to the wall and tend to put rotational forces on the device in the plane of the dust sheet 182. This might cause the device to work free which is undesirable. The applicant has addressed this problem by providing the first end 64 with the flat face 66 that extends in a horizontal . ë -: . e: . .e - 20 direction in use and that abuts the wall 170. This helps to inhibit the device 60 working free in the manner described above.

The projections 88, 90, 92, 94 are pressed down onto the dust sheet 182 and inhibit the same from being pulled away from the wall 170. Due to the shape and orientation of the projections 88, 90, 92, 94, they inhibit movement of the dust sheet 182 in one sense (rightwards in the sense of Figs. 8 and 9). Since the second end 72 of device 60 tends to press down on the dust sheet 182 as described above, any movement of the dust sheet away from the wall may tend to lift the second end 72 and may release the device from its secure position. The projections 88, 90, 92, 94 help to maintain the length of the portion of the dust sheet between the pin 86 and those projections, whereby lifting of the second end 72 is inhibited. Furthermore as the device 60 is already under tension substantially no upward movement of the second end 64 of the device is permitted. Any such movement is resisted by the pin 86 acting (directly of indirectly) against the gripper rod 176, against the stiffness of the body 62, and by contact between the first end 64 and the wall 170.

The two sets of projections 102, 103 also inhibit movement of the dust sheet 182 away from the wall to some extent, although this is not their primary function.

A plurality of such devices is used around a room each separated by between about 0.8m-1.2m and 0.25m-0.3m in from corners/angles, although the exact distance is not critical provided it is not much greater than the upper limits above. The devices serve to hold a dust sheet(s) in place for the duration of building or decorating works, for example. The devices are very quick to use, hold dust sheets securely, are quick to release, are lightweight and robust. Furthermore, no special tools . . -e :. ë : . . -. - 21

are required to use the device and the user does not need to lift the carpet to locate the gripper rod prior to use.

It is to be noted that the device 60 (or 10 or 120) is functional when the pin 86 is inserted substantially perpendicularly to the floor 172, although the best holding effect is obtained when used as described above.

Referring to Fig. 11 the steps of using the device in a second application are generally identified by reference numeral 200. This application is generally similar to that described in applicant's earlier publication GB-A-2 371 980. However, the device 60 offers improvements to the connecting member described in that publication.

Before the device 60 can be used, stairs 202 are covered by a dust sheet 204. At step 1 the second end 72 of the device 60 is offered up to the join between a tread 206 and a riser 208 at an angle of about 45 and substantially centrally across the width of the tread so that the points 114 of each curved projection are positioned adjacent the join. The two curved projections 110, 112 are pushed into the join, thereby pushing the dust sheet 204 into the crease of the carpet covering the stairs. The device 60 is pushed in until the curved projections 110, 112 are no longer visible. Depending on the material of the dust sheet 204, the curved projections 110, 112 may or may not penetrate it. This action brings the cross member 72 and two sets of projections 102, 103 into contact with the dust sheet 204 covering both the tread 206 and the riser 208 at their meeting point.

At step 2 the device is rotated downwardly about the contact between the curved projections 110, 112 towards the carpet covering the tread 206. The pin 86 is pushed down through the carpet and underlay until it contacts I.: I... ....e - 22 the tread 206. Since the pin 86 is longer than the thickness of most carpet/underlay combinations it can readily be pushed all the way through.

At step 3 the first end 64 of the device 60 is tapped with a rubber mallet to cause the pin 86 to penetrate the wooden tread 206 by a small depth (typically 2-4mm) and be retained by the grooves on the shank. The device 60 is now securely positioned on the tread 206 of the stairs. The first end 64 is held in place by the pin 86 and the second end 72 is held in place with the curved projections 110, 112 accommodated in the crease of carpet between the tread 206 and the riser 208 of the next stair up.

At step 4 a protecting member 210 can be releasably secured to the device 60 via one of the holes 80 and a fixing button 212 shown in exploded view in the Figure.

The fixing button 212 comprises a head portion 214 having a ridge 215 for contact with a user's fingers permitting the fixing button to be turned about its longitudinal axis; and a fixing part 216 in the form of an inverted "T". The protecting masher 210 comprises a sheet of plastics material formed into a shape comprising a substantially flat portion for accommodation on the tread, and a substantially curved portion for hooking over the end of the tread. The protecting member 210 also has a hole (not shown) through which the inverted "T" 216 can be inserted but through which the head portion 214 cannot pass.

The curved part of the protecting member 210 is firstly hooked over the end of the tread 206.In this way the hole of the protecting member 210 is aligned over the hole 80 of the device that will hold it in the right place. The inverted "T" 216 of the fixing button 212 is inserted through the hole in the protecting member 210 and through the hole 80 in the correct orientation. Once .: . .e ce. - 23

through the hole 80 the fixing button 212 is turned through 90 bringing the horizontal part of the "T" into contact with the portions of the body 62 either side of the hole 80 to hold the protecting member to the device 60. In this way the protecting member 210 is securely positioned on the tread 206. As a plurality of holes 80 is provided in the device 60, only one hole need be provided in the protecting member 210.

It will be apparent that the device 60 can be used to hold a dust sheet on stairs without using the protecting member 210, although use of a protecting member on each tread is preferred for safety reasons as it holds down a large area of the dust sheet.

During use, the device 60 retains the dust sheet securely in position whilst people use the stairs. When dust sheets are loosely positioned on stairs, they have a tendency to move up and down the stairs as a user climbs or descends. This can be dangerous as the user may snag a foot on a loose part of the dust sheet. The two sets of projections 102, 103 inhibit movement of the dust sheet down the stairs i.e. toward the outer edge of a tread. In particular, when the second end 72 of the device is pushed into the crease in the carpet, the projections 102, 103 press onto the dust sheet (and often penetrate) and the points resist movement of the dust sheet.

The projections 88, 90, 92, 94 and curved projections 110, 112 inhibit movement of the dust sheet up the stairs.

One particular problem that the applicant encountered with the clamp device in GB-A-2 371 980 is that it would often work loose of the carpet with repeated use of the stairs. Foot placement is typically either side of and in front of that device on the tread.

This causes the device to be tugged left and right by the dust sheet over time. Eventually this causes the device . . -e.:e.. .: . be. - 24

to work loose which is highly undesirable since the protecting member is no longer properly secured in place.

The device 60 (and the devices 10 and 120) addresses this problem with the cross member 72. In use, the cross member 72 is held in contact with the carpet at the join between the tread and the riser whereby rotation of the device 60 in a plane parallel to the tread is inhibited.

Furthermore since the pin 86 is held in position in the wood of the tread, that end of the device 60 is inhibit from lifting readily.

Should the projections 102, 103 penetrate the dust sheet, the space 108 between each projection serves to inhibit the projections from tearing the dust sheet.

To release the device 60 from the tread a claw hammer or ripper bar can be used to prize the pin 86 free from the tread.

The device 60 is easy to use in the stair application, provides a secure fitting for the protecting member whilst holding the dust sheet in place, is lightweight and is quick to remove.

The body of each of the devices may be injection moulded in one piece (i. e. comprising all of the features of the device with the exception of the metal pin), the head of the metal pin inserted into the molten plastic, and the plastic cured until the pin is held in position.

This provides a quick and easy method of manufacture. It is envisaged that the metal pin may be replaced with a plastic pin that may or may not be part of an injection moulding process. This is particularly advantageous for the device 10 that provides dust sheet holding functionality on the floor only. Where dual functionality (i.e. dust sheet holding on floors and stairs) is required in a device, the applicant believes that the metal pin performs better as it appears that some penetration of the tread by the pin is essential.

. . . :e . .: . a... -

Thus for the stair application the pin needs to be relatively long. The applicant has found about 22-23mm to be ideal, but the exposed length of the pin could be as short as 18mm, depending on carpet and underlay thickness. However, if the pin is too long it may not work properly in the floor application as the pin may reach the underlying floor (often of concrete) before the wedging and flexing effects are fully achieved. The applicant has found 22-23mm works very well for the floor application. Since buildings frequently have carpet/underlay combinations that are the same throughout this is somewhat surprising. In particular, the device meets the conflicting requirements of the floor and stair applications i. e. to penetrate the tread on the stairs, but not reach floor in a room, whilst holding a dust sheet securely in position in both circumstances.

The holes 80 of devices 60 and 120 provide a useful means for stacking a set of the devices for transport, storage and sale. The pin 86 of a second device may be inserted into the upper hole of a first device; the pin of a third device may be inserted through the upper hole of the second device and second hole of the first device, and so on.

It is envisaged that more than one pin may be provided on the device.

Claims

. , As:. I.: * I. - 26 CLAIMS: 1. A device for holding a dust sheet

in position over a floor covering, which device comprises first engaging means for directly or indirectly engaging a gripper rod under the floor covering whereby in use the device and dust sheet may be held substantially in position relative to the floor covering.
2. A device as claimed in claim 1, wherein in use the first engaging means provides a wedging of a part of the device between a wall and directly or indirectly said gripper rod.
3. A device as claimed in claim 1 or 2, wherein in use said wedging causes flexing of a flexing part of the device so as to apply a substantially continuous downward force to the dust sheet adjacent the wall.
4. A device as claimed in claim 3, wherein said flexing part comprises said first engaging means.
5. A device as claimed in claim 3 or 4, wherein said flexing part comprises a body of said device.
6. A device as claimed in any of claims 1 to 5, wherein said first engaging means comprises an engaging part for engaging a wall adjacent said floor covering, whereby in use upward movement of the device away from the floor covering is inhibited.
7. A device as claimed in any preceding claim, further comprising inhibiting means for inhibiting rotation of the device in a plane substantially parallel to a plane defined by the floor covering.
8. A device as claimed in claim 7, wherein in use said inhibiting means abut part of a wall adjacent said floor covering.
9. A device as claimed in claim 8, wherein said inhibiting means provide points of abutment that are at least approximately 35mm apart in use.
10. A device as claimed in any preceding claim, wherein ,.* .e.' *he - 27 said first engaging means is such that in use it penetrates said carpet and passes into a gap defined between said gripper rod and a wall adjacent the floor covering.
11. A device as claim in claim 10, wherein said first engagement means is such that, in use, said floor covering can be penetrated at an oblique angle, whereby the position of the gripper rod does not need to be determined prior to use of the device.
12. A device as claimed in claim 11, wherein said first engagement means is such that in use it penetrates said floor covering before engaging part of a wall, further penetration of the first engagement means into the carpet causing the device to be wedged between the wall and directly or indirectly said gripper rod.
13. A device as claimed in any preceding claim, wherein said first engagement means comprises a part that is positioned a distance from a first end of the device that is less than the distance between a wall and the gripper rod.
14. A device as claimed in claim 13, wherein said distance is between 6 and lOmm.
15. A device as claimed in any preceding claim, wherein said first engaging means comprises at least one pin for penetrating said floor covering in use.
16. A device as claimed in claim 13, wherein said pin comprises means for resisting removal of the pin from a floor covering into which it is inserted or driven.
17. A device as claimed in claim 16, wherein said means for resisting comprise one or more grooves on a shank of the pin.
18. A device as claimed in claim 15, 16 or 17, wherein said pin has an exposed length that is longer than the thickness of said floor covering.
19. A device as claimed in any of claims 15 to 18, ; i - 28 wherein said pin has an exposed length of approximately 18- 25mm.
20. A device as claimed in any preceding claim, further comprising gripping means for inhibiting movement of the dust sheet relative the device in use.
21. A device as claimed in claim 20, wherein said gripping means comprises a projection that is brought into contact with said dust sheet during use.
22. A device as claimed in claim 21, wherein said projection is adapted to resist movement of said dust sheet in at least one direction.
23. A device as claimed in claim 20, 21 or 22, further comprising a cross member supporting said gripping means.
24. A device as claimed in claim 23, wherein said cross member has a width that is wider than a body portion of the device.
25. A device as claimed in claim 24, wherein said gripping means are spaced across said cross member, whereby twisting of the device substantially parallel to a plane defined by said floor covering is inhibited.
26. A device as claimed in any preceding claim, further comprising a substantially flat surface that faces upwardly during use.
27. A device as claimed in any preceding claim, further comprising second engaging means for engaging a floor covering between the tread of a stair and the riser of the next stair up, whereby the device can hold dust sheets in position both on a floor and on stairs.
28. A device as claimed in claim 27, wherein said second engaging means are provided at an end of the device opposite to said first engagement means.
29. A device as claimed in claim 27 or 28, wherein said second engaging means comprises a projection for insertion into a fold of the floor covering between said tread and said riser.

a:.: A.; ... - 29
30. A device as claimed in claim 27, 28 or 29, wherein said projection comprises a curved spike having a point on or below a plane defined by the body of the device.
31. A device as claimed in claim 26, 27 or 28, wherein said first engagement means in use can pass through said floor covering to engage said tread.
32. A device as claimed in any of claims 27 to 31, further comprising at least one projection for inhibiting movement of the dust sheet up or down the stairs during use.
33. A device as claimed in claim 32, wherein said at least one projection projects forwardly and downwardly relative to the device in use.
34. A device as claimed in any of claims 27 to 33, further comprising means for inhibiting rotation of the device in a plane substantially parallel to a plane defined by the floor covering, whereby working loose of the device by the footsteps of users of the stairs is inhibited.
35. A device as claimed in claim 34, wherein said inhibiting means comprises a cross member for abutment with the floor covering at the join between the tread and the riser.
36. A device as claimed in any of claims 27 to 35, further comprising at least one hole or recess in a body portion of the device for releasable securing a protecting member to the device.
37. A device as claimed in any preceding claim, further comprising a material that provides elastic flexibility to a body of the device for accommodating said wedging function whilst providing a return spring force to assist holding said dust sheet in position.
38. A device as claimed in claim 37, wherein said material comprises a plastics, a reinforced plastics material or other material having a substantially . ...e A. ....e equivalent flexibility.
39. A method of manufacturing a device as claimed in any preceding claim, which method comprises the steps of forming a body portion and providing said body portion with said first engagement means.
40. A method as claimed in claim 38, wherein said forming step comprises the step of injection moulding said body portion.
41. A method as claimed in claim 39, further comprising the step of inserting said first engagement means into said body portion whilst said body portion is uncured.
42. A kit for holding down dust sheets in a room, which kit comprises a plurality of devices as claimed in any preceding claim.
43. A kit as claimed in claim 42, further comprising a dust sheet for use with said plurality of devices.
44. A kit as claimed in claim 42 or 43, further comprising a protecting member for use with a device, that arrangement being such that, in use, the device can retain the protecting member in position over part of a tread of a flight of stairs.
45. A kit as claimed in claim 42, 43 or 44, further comprising a set of instructions for using each device substantially as herein described or substantially as shown in Fig. 10 and/or Fig. 11 of the accompanying drawings.
46. A device substantially as hereinbefore described with reference to and as shown in Figs. 1, 2 and 3 of the accompanying drawings.
47. A device substantially as hereinbefore described with reference to and as shown in Figs. 4 and 5 of the accompanying drawings.
48. A device substantially as hereinbefore described with reference to and as shown in Figs. 6 and 7 of the accompanying drawings.

:: . . : . . . . . . ë - 31
49. A device for holding a dust sheet in position on stairs, which device comprises an engagement means for penetrating a floor covering and engaging a tread thereunder.