GB2522002A

GB2522002A - Access cover assembly

Info

Publication number: GB2522002A
Application number: GB1319651.4A
Authority: GB
Inventors: Ralph Thomas; Paul Simpson
Original assignee: Wade International Ltd
Current assignee: Wade International Ltd
Priority date: 2013-11-07
Filing date: 2013-11-07
Publication date: 2015-07-15
Also published as: GB201319651D0

Abstract

An access cover assembly for an opening in a floor has a generally rectangular frame 10 adapted to secure around the opening, and a cover 11 fitting within the frame and movable between closed and open positions. A pair of wheels 26 is provided at one end 19 of the cover and a lifting mechanism, such as a lever (20, figure 9), is arranged to lower the wheels into engagement with the frame and so lift the one end of the cover above the floor surface. At the other end 32 of the cover there is a roller 38 for running on the floor and a pull-handle 39 for lifting and moving the other end so that the roller may be moved onto and run on the floor. Operation of the lifting mechanism to raise the one end of the cover and then pulling on the pull handle at the other end of the cover allows the cover to be raised and then rolled from its closed position to its open position.

Description

ACCESS COVER ASSEMBLY

This invention relates to an access cover assembly primarily intended for use in a floor of a commercial or industrial building, but which may be used in other situations where an opening in the floor is to be covered but where access is required to that opening from time-to-time.

Large access cover assemblies such as those suited for man-access and so of 600mm diameter and greater may be relatively heavy and so difficult to remove from the closed position when access is required below the cover.

Modern health and safety rules usually require the use of machinery to lift and move a relatively heavy cover, or more than one person must perform this io operation.

In other environments, such as a domestic dwelling, it still may be necessary to provide an access cover over an opening in the floor but in such a case it is preferable for the cover to be arranged to form an airtight or hermetic seal with a frame let into the floor. In addition, a floor covering material, such as is carpeting or a flexible plastics sheet such as vinyl flooring, may be provided on the floor. In that case, the carpeting or flooring must be cut to the shape of the access opening and for aesthetic reasons it is preferred for a matching piece of the carpeting or flooring to be secured to the upper face of the cover.

It is a principal aim of the present invention to provide an access cover assembly which permits opening and closing by one person without use of significant muscular effort or lifting equipment even for a relatively heavy cover, and moreover which in its preferred aspects also permits floor covering material to be secured around the frame of the assembly and also to the cover itself, in a secure and reliable manner.

According to this invention, there is provided an access cover assembly for an opening in a floor, comprising a generally rectangular frame adapted to be secured to the floor around the opening, a cover fitting within the frame and movable between closed and open positions, and means to facilitate the moving of the cover between said positions, said means comprising at one end of the cover a pair of wheels disposed one to each side of the cover, a manually-operable lifting mechanism to lower the wheels into engagement with running surfaces to each side of the frame and lift said one end of the cover above the floor surface, and at the other end of the cover at least one roller for running on the floor and a pull-handle for lifting and moving said other end of the cover so that the roller may run on the floor, whereby operation of lifting mechanism to raise said one end of the cover followed by pulling on the pull-handle at the other end of the cover allows the cover to be raised and then rolled from its closed position to its open position.

It will be appreciated that the access cover assembly of this invention is arranged so that only one end of the cover is raised at a time. A lever mechanism is provided to lift one end of the cover when the cover is to be opened and once that one end has been raised by the mechanism, then the other end of the cover may be raised by pulling on the pull-handle provided at that other end. This brings the roller at the other end of the cover on to the floor surface so that the cover may thereafter may be rolled along the floor surface merely by pushing the cover from the one end or pulling the cover from the other end.

Preferably, the frame comprises interconnected inner and outer frame elements with a channel defined between the frame elements. In this case, the cover should fit to the inner frame elements, preferably with a seal formed thereto for example by way of a gasket disposed between the inner frame elements and the cover. Such a gasket may be attached to the underside of the cover.

The channel between the inner and outer frame elements along the sides of the frame may define the running surfaces for the wheels. Such running surfaces may simply comprise flat surfaces extending along the channel between the frame elements.

Advantageously, each wheel is mounted on an arm pivoted to the cover and there is a lifting handle connected to the arm to cause pivoting movement thereof. The arms may be connected together so that both wheels may be lowered onto or lifted from the running surface, by manipulation of the handle.

In a preferred arrangement, there is a shaft extending across the cover at said one end thereof, each arm being carried by the shaft for simultaneous angular movement, and there is a lifting handle connected to the shaft and movable between a non-use position where the handle lies in the channel between the inner and outer frame elements at said one end when the cover is in the closed position, and an in-use position where the handle upstands from the frame for effecting rotation of the shaft. The handle may be telescopically extensible when in the in-use position, thereby to increase the leverage thereof. Each arm may be arranged as an over-centre mechanism such that when the cover is in its raised position, the arm is in a stable position.

A guide rail may be arranged on the underside of the cover with a slider engaged with that guide rail, the slider being pivoted to the frame by means of at least one arm for movement between raised and lowered positions. In this way, by pulling on the pull-handle at the other end of the cover, the slider will be constrained by the at least one arm to pivot to a raised position, so lifting that other end of the cover. From that position, the cover may be moved to its open position by the wheels and rollers running on the floor surface.

A rectangular clamping collar may be arranged to fit closely to the cover and also over the channel between the frame elements, so as to close that channel. Preferably, the clamping collar is hold in position by screws passing through holes in the clamping collar and threaded into the main frame of the cover assembly. Separate clamping strips may be provided to hold down cut edges of any flooring material provided on the floor and on the cover.

By way of example only, one specific embodiment of an access cover assembly of this invention will now be described in detail, reference being made to the accompanying drawings in which:-Figure 1 is an isometric view of the embodiment of access cover assembly from above, with the cover partially open and also showing a clamping collar; Figure 2 is a plan view of the access cover assembly, with the cover in a closed position; Figure 3 is an underplan view of the assembly of Figure 2; Figure 4 is a plan view of the assembly of Figure 2 but with the cover in an open position; Figure 5 is a side view of the assembly of Figure 4; Figure 6 is a view on an enlarged scale of the part of the assembly encircled in Figure 5; Figure 7 is an isometric under-view of the assembly in a closed position; Figure 8 corresponds to Figure 7 but with the cover partially open; Figure 9 is a partial isometric view on an enlarged scale of a lever mechanism for raising one end of the cover; Figures bA, lOB and 100 are sequence isometric views showing the use of the lever mechanism; Jo Figure 11 is an isometric under-view on an enlarged scale of part of the assembly in Figure 7, with the cover closed; and Figure 12 corresponds to Figure 11 but with the cover partially open.

The embodiment of cover assembly comprises a main frame 10 for letting into a floor around an opening giving access to a duct or service point beneath the floor, a sliding cover 11 and a rectangular clamping collar 12. The main frame 10 is of rectangular shape and is configured for fitting into a floor at the time that is installed. Each side of the frame comprises interconnected inner and outer frame elements 13,14 with a channel 15 formed between those frame elements. The cover 11 is adapted to fit in an airtight manner to the inner frame elements 13 of the main frame 10, and for this purpose a gasket ring (not shown) may be furnished on the underside of the cover, to engage corresponding surfaces of the inner frame elements. When fully closed, the cover is held in position by the clamping collar 12, secured to the main frame 10 by means of screws 16 extending through apertures in the clamping collar and threaded into bushes 17 provided on the main frame 10.

If required, sheet flooring material (not shown) may be cut to fit to the main frame 10 and four clamping strips (not shown) used to secure the cut edges to the frame. A separate piece of the sheet flooring material may be cut to the size and shape of the cover 11, and the cut edges of that piece being secured to the cover by four more clamping strips (also not shown).

A mechanism is provided to facilitate opening and closing of the cover 11, once the clamping collar 12 has been removed from the assembly. The mechanism serves to raise the cover so that the underside thereof is above the floor level whereafter the cover may be slid along the floor surface. At one end 19 of the cover, the mechanism comprises a shaft 22 extending across the width of the cover and having a pair of lifting arms 23 secured thereto, one adjacent each side of the cover, respectively. Each arm 23 carries a wheel 26 at its end remote from shaft 22, for a purpose to be described below. Each end of the shaft carries a respective boss 21 externally of the cover, and pivoted to one of those bosses by screw 25 is a two-piece telescopic lifting handle 20.

Should access to the handle be inconvenient at any particular installation site, the handle may be removed from one boss 21 and then pivoted to the boss at the other end of the shaft 22.

Figure 1OA shows the lifting handle 20 in its non-use or parked position, with the two parts telescoped together and lying in the channel 15 between the inner and outer frame elements 13,14 at the one end of the main frame. When the cover is to be opened, the handle 20 is pivoted about screw 25 so as to upstand as shown in Figure lOB and is then extended as shown in Figure 100.

The handle is then used to rotate the shaft in a counter-clockwise sense (in Figure 9) thereby to move the lifting arms 23 from their parked positions lying parallel to the side wall of the cover, to the position shown in Figure 9. The base wall of the channel 15 serves as a running surface for the wheel 26 of each arm 23, the wheel being forced into engagement with that running surface by movement of the handle to rotate the shaft 22. The length of the arm 23 is such that movement of the shaft to the position of Figure 9 lifts the one end 19 of the cover 11 to the position shown for example in Figures 5 and 6.

Movement of the lifting arm 23 on manipulation of the handle 20 from the position of Figure 1 OB to that of Figure 9 takes the lifting arms 23 over-centre, through a position where the arms extend essentially perpendicularly to the main frame 10 and the cover 11. The weight of the lifted cover will maintain the arms in the position shown in Figure 9, until the handle 20 is again manipulated to rotate the shaft 22 in a clockwise sense. Further, the inner frame element 14 includes a lip 27 which, when the cover has been lifted and slid through a small distance from its closed position, prevents the cover being manually lifted wholly clear of the frame by the engagement of the wheels 26 with the lips of the inner frame elements on the two sides of the frame.

A guide rail 29 is mounted on blocks 30,31 provided on the underside of the cover so that the rail extends centrally from the one end 19 of the cover to the other end 32 thereof, the rail being spaced by a small distance from the under-surface of the cover. A slider 33 is carried on the guide rail 29 and is pivoted to a pair of crank arms 34 journalled to a bracket 35 secured to the main frame 10, at the other end thereof. A pair of ribs 36 extend along the length of the cover spaced one to each side of the guide rail 29 and each rib carries a channel member 37 rotatably supporting a roller 38. At the other end 32 of the cover opposite the one end 19, externally on the end wall thereof. there is provided a pull-handle 39 which in this embodiment is in the form of a relatively loose length of wire cable or similar material but could take other forms. The pull-handle may be grasped and raised above the upper surface of the cover before tension appears in the cable to apply a lifting force to the cover.

When the cover is to be opened, the clamping collar 12 is removed by releasing the screws 16 and lifting the clamping collar away from the assembly.

The handle 20 is turned from its non-use or parked position (Figure bA), to its in-use position (Figure lOB) and is then extended (Figure lOG) whereafter the handle is moved to the position of Figure 9, so causing the lifting arms 23 to turn and engage the wheels 26 with the running surfaces at the base of the channel 15 between the inner and outer frame members 13,14, at the one end 19 of the cover. This lifts the one end of the cover to slightly above the surrounding floor level. Then, the pull-handle 39 at the other end of the cover is grasped and pulled upwardly and at the same time pulled away from the one end of the cover. This causes the crank arms 34 to pivot about their connection to the bracket 35, from the position of Figure 7 to that of Figure 8. This brings the rollers 38 on to the floor surface adjacent the other end of the cover. After that, the cover may be slid open as far as is required, perhaps to the maximum open position shown in Figures 4 and 5. During this sliding movement the entire weight of the cover is taken by the wheels 26 and the rollers 38. The guide rail 29, interacting with the slider 33, serves to ensure the cover slides linearly, parallel to the sides of the main frame, and prevents the cover being lifted out as if a conventional access cover.

Replacement of the cover is achieved simply by sliding the cover from the open position of Figures 4 and 5 back towards the closed position. As that is reached, the slider 33 will be engaged by the mounting block 31 of the cover, so automatically lowering the other end of the cover by rotation of the crank arms 34. Once the other end 32 has engaged the main frame IC, the one end 19 may be lowered by turning the lifting handle 20 clockwise, so lowering the other end of the cover to engage the main frame, whereafter the handle 20 may io be collapsed and parked once more in the Figure iDA non-use position. Finally, the clamping collar 12 may be replaced, using the screws 16, to give an airtight assembly.

Claims

CLAIMS1. An access cover assembly for an opening in a floor, comprising a generally rectangular frame adapted to be secured to the floor around the opening, a cover fitting within the frame and movable between closed and open positions, and means to facilitate the moving of the cover between said positions, said means comprising at one end of the cover a pair of wheels disposed one to each side of the cover, a manually-operable lifting mechanism to lower the wheels into engagement with running surfaces to each side of the frame and lift said one end of the cover above the floor surface, and at the other end of the cover at least one roller for running on the floor and a pull-handle for io lifting and moving said other end of the cover so that the roller may run on the floor, whereby operation of lifting mechanism to raise said one end of the cover followed by pulling on the pull-handle at the other end of the cover allows the cover to be raised and then rolled from its closed position to its open position.
2. An access cover assembly as claimed in claim 1, wherein the frame is comprises interconnected inner and outer frame elements with a channel defined between the frame elements, the cover fitting to the inner frame elements.
3. An access cover assembly as claimed in claim 2, wherein the running surfaces are defined between the inner and outer frame elements along the sides of the frame.
4. An access cover assembly as claimed in claim 2 or claim 3, wherein each wheel is mounted on an arm pivoted to the cover and there is a handle connected to the arm to cause pivoting movement thereof so as to lower the wheel on to or lift the wheel from the respective running surface.
5. An access cover assembly as claimed in claim 4, wherein there is a shaft extending across the cover at said one end thereof, each arm being carried by the shaft for simultaneous angular movement, and there is a lifting handle connected to the shaft and movable between a non-use position where the handle lies in the channel between the inner and outer frame elements at said one end when the cover is in the closed position, and an in-use position where the handle upstands from the frame for effecting rotation of the shaft.
6. An access cover assembly as claimed in claim 5, wherein the handle is removably pivoted to a boss mounted on the shaft whereby the handle may be turned about the pivotal connection between the non-use and in-use positions.
7. An access cover assembly as claimed in claim 5 or claim 6, wherein the handle is telescopically extensible when in the in-use position, thereby to increase the leverage thereof.
8. An access cover assembly as claimed in any of claims 4 to 7, wherein each arm mounting a respective wheel is arranged as an over-centre mechanism whereby movement of the handle to lift said one end of the cover io moves the arms over-centre to stable positions where said one end of the cover is raised.
9. An access cover assembly as claimed in any of the preceding claims, wherein said other end of the cover is provided with a pair of rollers spaced across the width of the cover.
10. An access cover assembly as claimed in any of the preceding claims, wherein the pull-handle provided at the other end of the cover is disposed within the channel between the inner and outer frame elements when the cover is in its closed position and the pull-handle is not in use.
11. An access cover assembly as claimed in any of the preceding claims, wherein there is a guide rail provided on the underside of the cover, a slider is engaged with the guide rail and is mounted on the frame at the other end thereof for movement between raised and lowered positions, the guide rail running in the slider as the cover is moved between its closed and open positions.
12. An access cover assembly as claimed in claim 11, wherein the slider is mounted on a crank arm pivoted to the frame whereby the block automatically moves to its raised and lowered positions on movement of the cover between its closed and open positions.
13. An access cover assembly as claimed in any of the preceding claims, wherein a gasket is provided between the underside of the cover and the main frame, to effect a seal therebetween.
14. An access cover assembly as claimed in claim 13, wherein the gasket is attached to the underside of the cover, to effect a seal to the inner frame elements of the main frame.
15. An access cover assembly as claimed in any of the preceding claims, wherein a removable clamping collar is provided to hold down the cover in its closed position.
16. An access cover assembly as claimed in claim 15 and in which sheet-like flooring material is provided on the floor around the opening therein and on the cover, and the clamping strips are provided to hold down the cut edges of the sheet-like flooring material, said clamping strips being secured to the frame and to the cover as appropriate.
17. An access cover assembly as claimed in claim 1 and substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.