GB2551303A

GB2551303A - Perforating tool

Info

Publication number: GB2551303A
Application number: GB1715156.4A
Authority: GB
Inventors: Warner Pritpal
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-09-20
Filing date: 2017-09-20
Publication date: 2017-12-13
Anticipated expiration: 2037-09-20
Also published as: GB2566763B; GB201715156D0; GB201720726D0; GB2551303B; GB2566763A

Abstract

A wallpaper perforating tool 10 is used to perforate wallpaper to enable a solvent, which may be water or steam, to reach an adhesive layer on the paper's rear face and so soften or dissolve it, facilitating removal of the paper from a wall. The tool has a housing 12 which has an opening 24. A rotor 16 is mounted within the housing for rotation about an axis which is fixed with respect to the housing. The housing has a registration surface 22 for contacting the wallpaper. The axis of the rotor is substantially parallel to the wallpaper when the registration surface is in contact with it. A powered drive is provided to turn the rotor and may take the form of an air driven turbine (14, Fig.2). The rotor carries projections 28 which extend radially outwardly through the opening in the housing, to perforate the wallpaper. The housing may be provided with a port (20, Fig.2) for connection to an air extraction device such as a domestic vacuum cleaner.

Description

PERFORATING TOOL

The invention relates to a tool used to perforate wallpaper. The tool may be used to enable a solvent, which may be water or steam, to reach an adhesive layer on the paper's rear face and so soften or dissolve it, facilitating removal of the paper from a wall.

When re-decorating a room it is often necessary to remove existing paper from the walls before applying a fresh covering such as paint or a new wallpaper. The removal process is laborious, typically involving scraping the wallpaper with a hand tool. It can be facilitated by softening the adhesive layer on the wall-facing side of the paper using water, steam or some other suitable solvent, but to enable the solvent to reach the adhesive the paper typically needs to be perforated in some manner. This applies especially but not exclusively to water-impermeable wallpapers.

The prior art contains a range of tools for perforating wallpaper.

Some such tools use manual power alone. An example which is widely commercially available has a spiked roller rotatably mounted to an elongate handle akin to a broom handle, the roller's axis of rotation being perpendicular to the handle. The roller is run across the wallpaper with firm pressure so that the spikes penetrate the paper.

The effectiveness of this device is highly variable because the size and depth of the perforations depends on the force applied by the user. The perforations can be too small and so expose insufficient backing layer, or not deep enough to penetrate multiple layers of wallpaper, both of which will result in the user having to perforate, soak and scrape the same area multiple times. Perforations can also be too deep and damage the underlying plaster.

The same drawbacks apply to the scoring tool disclosed in US3738001, which has a curved blade with a castellated cutting edge fixed to an elongate handle. The blade in this case does not rotate but is simply drawn across the paper surface to scrape it, involving arduous manual effort. GB2053767 and US4274202 both disclose handheld perforating devices having a pair of spiked rollers whose axes are inclined one to the other at an obtuse included angle, the effect being to cause the spikes to move laterally while in engagement with the wallpaper, tearing it somewhat to provide elongate slits rather than point perforations. The manual effort needed to roll the device across the paper is however increased by this tearing action, and again the depth of the perforations is dependent on the pressure applied by the user, and is therefore undesirably variable.

The device of US6163966, has a pair of toothed wheels for scoring the paper, their axes again being inclined one to the other to provide a tearing effect. The wallpaper removal tool of WO2008/124398 has multiple pairs of toothed wheels inclined one to the other. Here again, the user's manual effort drives the wheels and their tearing action, requiring significant manual exertion.

Use of manually driven perforators can prove to be laborious and slow. Laborious because of the need to apply force and the resistance of the wallpaper, especially while reaching overhead. Slow because of the tiring nature of the work, and because of the need to reposition ladders or platforms used to reach the top of walls and ceilings.

Wallpaper perforating devices using an electric motor to drive a rotary mechanism have been proposed in the past. Examples are to be found in EP1688270, SE463019, US370880 and US2006/174740. A feature common to all the powered devices disclosed in these documents is that the powered drive turns some form of carrier about an axis which is perpendicular to the plane of the wall/wallpaper in use. In the device of US3708880 four circular but fixed (i.e. non-rotatable) blades are carried on a "cutter-supporting body" mounted to the chuck of an electric drill. The other three documents all describe arrangements having a three-spoked carrier turned about the aforementioned axis perpendicular to the plane of the paper by an electric drive, each arm having freely rotatable wheels or drums upon it to provide the perforating effect. These are somewhat complex devices mechanically and potentially subject to clogging by the material that they cut and score. They are also heavy, making the task more burdensome for the user.

The present invention is intended to provide a wallpaper perforating device which is simple and robust but also rapid and effective in use, and whose operation does not require excessive manual effort.

The words "paper" and "wallpaper" are used interchangeably herein. Both refer to any form of thin wall covering in sheet form.

In accordance with a first aspect of the present invention there is a wallpaper perforating tool comprising a housing having an opening and having a registration surface for contacting a surface of the wallpaper, a rotor mounted within the housing for rotation about an axis which is defined with respect to the housing and is substantially parallel to the said surface of the wallpaper when the registration surface is in contact with it, a powered drive coupled to the rotor to rotate it about the said axis, and projections formed upon the rotor which extend outwardly through the opening in the housing, to perforate the wallpaper. A rotor turning about an axis parallel to the plane of the wall/paper provides effective scoring without undue constructional complexity. Its powered drive minimises manual effort. The registration surface defines a maximum depth of cut and can serve to ensure consistency in the depth of penetration of the projections into the paper. The axis of rotation of the rotor is static with respect to the housing while the tool is in use, but its separation from the registration surface may be adjustable to enable the depth of penetration of the spikes to be adjusted. This may be achieved by small movement of the member forming the registration surface, or of the axis of rotation of the rotor. A screw mechanism may be provided for making such adjustment. This may comprise a worm and wheel arrangement. A further problem associated with the prior art concerns safety. Existing perforating tools create a shower of potentially hazardous debris particles which can include lead-based paint, which is still commonly found in UK homes, and arsenic-based wallpaper which was in common use in the 19th century and so can be encountered during renovations. The ejection of cut material from the known devices is also an undesirable source of mess in the room, potentially dirtying or even causing damage to carpets, furnishings and so on.

In a preferred embodiment of the present invention, the housing is provided with a port for connection to an air extraction device. In such an embodiment the powered drive may comprise an impeller or other air driven mechanism to rotate the rotor. The air extraction device used may be a domestic vacuum cleaner. This type of embodiment has several advantages. Cut or shredded material produced by the perforating process is extracted by a flow of air through the housing, to be captured without posing a danger to health and without causing mess in the room. Use of air drive makes a battery or electrical connection to the perforating tool unnecessary. The tool itself, lacking an electric motor, can be lightweight and economical to manufacture.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:-

Figure 1 is a side view of a first wallpaper perforating tool embodying the present invention;

Figure 2 is a further side view of the tool represented in Figure 1, a side wall and a base wall being omitted to reveal internal detail;

Figure 3 is a view from beneath of a second wallpaper perforating tool embodying the present invention;

Figure 4 is a side view of a third wallpaper perforating tool embodying the present invention, a side wall being omitted to reveal internal detail;

Figure 5 is a view from beneath of a fourth wallpaper perforating tool embodying the present invention; and

Figure 6 is a view from one side of a fifth wallpaper perforating tool embodying the present invention.

The wallpaper perforating tool 10 depicted in Figures 1 and 2 comprises a housing 12 containing, in summary, a rotary air driven turbine 14, a rotor 16, a transmission 18 which drivingly couples the turbine 14 to the rotor 16, and a tubular air port 20.

The housing 12 is a hollow structure which may for example be of injection moulded plastics. It has a base wall providing a registration surface 22, which in the present embodiment is planar and flat. An opening 24 is formed in the base wall, through the registration surface 22. Side walls 25 upstanding from the base wall define an internal space for the working parts of the tool, which are thus guarded to minimise the risk of injury e.g. by accidental insertion of a fingertip.

The rotor 16 is mounted inside the housing 12 through suitable rotary bearings at both its ends, which are not seen in the drawings but may be plain or may for example be ball bearings. The rotor 16 comprises a cylindrical rotor body whose outer surface is provided with a plurality of projections 28 for perforating the wallpaper. In the present embodiment these projections take the form of upstanding conical spikes with sharp tips, although they may take a range of different shapes in other embodiments. The rotor 16 lies adjacent the opening 24 in the base wall so that its cylindrical body 26 is wholly within the housing 12 but the projections 28 extend outwardly of the plane defined by the registration surface 22, to engage the wallpaper itself. The distance that the projections extend beyond that plane is thus the effective limit of the depth to which the projections 28 can penetrate the wallpaper on a flat wall.

The turbine 14 of the present embodiment is an impulse turbine. The air port 20 is directed along a line which is offset from the turbine's axis so that air flow into the air port 20 impinges on the turbine wholly or predominantly to one side of the axis, and the turbine 14 has vanes 30 upon which this offset flow acts to turn the turbine.

The axis of the turbine 14 is parallel to that of the rotor 16 but is in this example offset from it, so that transmission 18 is needed to transmit rotary drive from the turbine 14 to the rotor 16. In the present embodiment the transmission 18 is a belt drive which is housed in its own compartment 32 to avoid it being clogged by shredded wallpaper or other foreign matter. The compartment 32 is defined by an upright bulkhead 34 within the housing 12. The turbine 14 has a shaft (not seen) which passes through the bulkhead 34 to carry a drive wheel 38 within the compartment 34. The rotor 16 has a shaft (not seen) which passes through the bulkhead 36 to carry a driven wheel 40 in the compartment 32. A drive belt 42 runs upon the drive and driven wheels 38, 40 to transmit rotary drive from one to the other. In the illustrated example the wheels 38, 40 have the same diameters to provide a 1:1 drive ratio but in other embodiments the transmission 18 may provide a step up or a step down in speed from the turbine 14 to the rotor 16.

The air port 20 serves two functions in the present embodiment. As well as providing for flow of air to the housing 12 it serves to engage with a tubular conduit 42 used as a handle for the tool 10. For this purpose the air port 20 is inclined with respect to the registration surface 22, making it easy for a user holding the conduit 42 to present the tool to the wall with registration surface 22 flat against it. Typically the tool 10 will be used with a domestic cylinder type vacuum cleaner, in which case the conduit 42 will be the tube that forms the vacuum cleaner's handle. The tool 10 may be supplied with one or more adapters to be interposed between the conduit 42 and the air port 20, to enable the tool to receive and couple to handles from multiple different vacuum cleaner types and/or manufacturers.

In other embodiments the functions of air port and handle may be served by separate components.

The housing 12 is configured such that air drawn through it by the air extraction device follows the following route: the air enters the housing 12 through the opening 24 (and in the present embodiment this is the only route for entry of air to the housing); it flows past the rotor 16 to entrain shreds of cut wallpaper and other material released by the perforating process; it then passes the turbine 14 to drive the rotor 16; and it then exits the housing 12 through the air port 20.

In use, the tool 10 is to be run across the surface of the wallpaper to be scored. The length of the conduit/handle 42 makes it possible to reach a large area of wall whilst standing still, and to reach high areas without need of a stepladder. The registration surface 22 is maintained adjacent to or in contact with the wallpaper surface, and roughly parallel to it, by the user. The projections 28 of the roller 16 engage the wallpaper through the opening 24 and as they turn produce the required perforations, after which a solvent - be it steam, water or some other substance - is applied to loosen the paper preparatory to its removal.

The wallpaper perforating tool 100 depicted in Figure 3 differs from that of Figures 1 and 2 in that the turbine 114 is co-axial with rotors 116, making the transmission 18 unnecessary. The tool 100 has first and second rotors 116a, 116b which are on opposite sides of the turbine 114 and directly coupled to it through shafts (not seen) journaled in respective bulkheads 36a, 36b. The bulkheads constrain air flow past the turbine 114, ensuring that the incoming air passes over the turbine to drive it. The air port 120 communicates with the volume between the bulkheads 36a, b, where the turbine 114 is housed.

In this embodiment housing 112 is open toward the wallpaper in use - it lacks the base wall of the earlier embodiment. The registration surface 122 for engaging with the wallpaper to define the maximum depth of cut is formed by the lower periphery of upstanding side walls 125. This registration surface 122 defines a first opening 124a associated with the first rotor 116a and a second opening 124b associated with the second rotor 116b.

Figure 4 depicts a wallpaper perforating tool 200 which differs from the earlier embodiments in using an electric motor 250 to drive the rotor 216. The general form of the housing 212 in this embodiment is similar to that of the Figure 1 embodiment and it houses a single rotor 216 driven via a belt 242, but in this case the belt drive wheel 238 is carried on the shaft of the electric motor 250. This version of the tool 200 is corded - that is, it receives mains electrical power through electrical cord 252.

Figure 5 shows a wallpaper perforating tool 300 similar to that of Figure 4 but differing from it in two respects: it has an onboard battery pack 354 to drive the electric motor 350. A fixed mains connection may therefore be dispensed with, although Figure 5 shows an electrical cord 352 which serves as a charging lead; the belt drive is dispensed with in this embodiment. Instead the electric motor 350 is arranged with its shaft (not seen) coaxial with the rotor 316 and coupled to it. A stub 354 on the motor's casing serves to react the motor's torque to the housing 312 and the motor itself is largely contained within the rotor 316, which is hollow. This makes for a compact arrangement without the need to extend the housing laterally to accommodate the motor 350.

In all of the above described embodiments the registration surface 22/122 which defines the maximum depth of cut lies in a flat plane. Figure 6 illustrates another option in this respect. The wallpaper perforating tool 400 of this drawing is a variant of that depicted in Figure 1, differing from it in that the registration surfaces 422 formed by the lower peripheries of the housing walls 425 lie on a locus which is circular, when viewed along the direction of the axis of the rotor 416. The centre of this circular locus coincides with the rotor's axis. The effect is that some variation of the angle between the tool and the wall can be accommodated without causing the rotor's spikes 428 to disengage from the wallpaper, and without changing the maximum depth of cut.

The aforegoing embodiments are presented by way of example and not limitation. Numerous further variations are possible without departing from the scope of the invention as set out in the appended claims.

Claims

1. A wallpaper perforating tool comprising a housing having an opening and having a registration surface for contacting a surface of the wallpaper, a rotor mounted within the housing for rotation about an axis which is defined with respect to the housing and is substantially parallel to the said surface of the wallpaper when the registration surface is in contact with it, a powered drive coupled to the rotor to rotate it about the said axis, and projections formed upon the rotor which extend outwardly through the opening in the housing, to perforate the wallpaper.

2. A tool as claimed in claim 1 in the housing is provided with a port for connection to an air extraction device.

3. A tool as claimed in claim 2 in which the powered drive comprises an impeller or other air driven mechanism to rotate the rotor.

4. A tool as claimed in claim 3 in which the air port is configured to connect to a domestic vacuum cleaner.

5. A tool as claimed in any of claims 2 to 4 in which the form of the housing is such as to cause waste material released by the perforation process to be entrained in airflow to the extraction device.

6. A tool as claimed in any preceding claim in which the air port is coupled to an elongate conduit for connection to the air extraction device, the configuration being such that the elongate conduit is able to serve as a handle through which the tool is held in use.

7. A tool in which the powered drive is drivingly coupled to the rotor through a transmission.

8. A tool as claimed in claim 7 in which the transmission comprises a drive belt.

9. A tool as claimed in any of claims 1 to 6 in which the powered drive comprises an air driven turbine which is coaxial with the rotor and coupled to it through a shaft.

10. A tool as claimed in any preceding plane in which the registration surface lies a flat plane.

11. A tool as claimed in any of claims 1 to 9 in which the registration surface lies on a circular locus whose centre coincides with the rotor's axis of rotation.

12. A tool as claimed in any preceding claim in which the rotor comprises a cylindrical body carrying the said projections.

13. A tool as claimed in any preceding claim in which the projections have a conical shape.

14. A tool as claimed in claim 1 in which the powered drive comprises an electric motor which is at least partially contained in the rotor.