GB2388804A

GB2388804A - Cutting apertures in access panels

Info

Publication number: GB2388804A
Application number: GB0211565A
Authority: GB
Inventors: James Marrion Kelly
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-05-20
Filing date: 2002-05-20
Publication date: 2003-11-26
Anticipated expiration: 2022-05-20
Also published as: GB2388804B; GB0211565D0

Abstract

A method of cutting an access panel on site to form a circular aperture in the panel at a desired location, comprising the steps of: supporting the panel on a portable panel holder 1; mounting on the panel holder 1 a detachable cutting tool 13 having a hollow, cylindrical cutting blade (19, fig 3) adjusting the relative positions of the panel and cutting tool 13 to position the cutting blade (19, fig 3) at a desired location of the panel; securing the panel in position with respect to the panel holder 1; and operating the cutting tool 13 to cut the aperture in the panel. The cutting tool blade (19, fig 3) is such that it forms the panel apertures by what is generally known as trepanning.

Description

PATENTS ACT 1977

P 1 6472GB-LDH/ATB/cg "Cutting Apertures in Access Panels" THIS INVENTION relates to a method of cutting and a cutter for cutting circular apertures in access panels, and in particular concerns a method of cutting and a portable access panel cutter that can be used effectively on-site.

Many modern buildings are constructed with a substantial space below the floors of the rooms, with the space being utilised to supply services. These services may include power, ventilation, telephone connections, data connections and so forth.

The floors of buildings constructed in this fashion typically comprise access panels, in which apertures can be cut to gain access to desired services.

For instance, if a desk is positioned in the middle of an office, the desk may be positioned over a suitable aperture in an access panel in the floor of the office, so that power can be supplied for a computer on the desk, to provide a connection for a telephone on the desk, and to allow the computer to connect to a computer network.

Service components, such as electrical/electronic connectors or air diffusion grills of standard sizes are provided to fit into correspondingly-sized apertures in access panels, to provide convenient connections to the desired services. Such service components incorporate peripheral flanged grommets intended to support and seal the component in the aperture. These grommets are typically circular, and accordingly circular apertures are generally provided in access panels in appropriate places.

( Conventionally, circular apertures are cut in access panels using CNC (computer numerically controlled) machines. CNC machines are typically large, require a 240V power supply and are permanently installed in a factory or other off-site facility. Hence, it is helpful to know the sizes and locations of apertures that are to be required in access panels prior to delivery of the access panels to a construction site, so that these apertures can be formed by a CNC machine prior to delivery of the access panels.

Alternatively, if a circular aperture is required in an access panel onsite and at short notice, this is done by tracing the size of aperture required on a surface of the access panel and cutting the aperture using a hand-held jig saw or similar saw. Clearly, it is very difficult and time consuming to cut an accurate circular aperture in an access panel using a jig saw, and apertures cut in this fashion are typically rather uneven and imprecise in dimensions. This low tolerance can lead to problems, since the grommets of the service components are typically provided with only a 5mm flange which overlies the portion of the access panel surrounding the aperture, and the cutting of an imprecise aperture serves to reduce this already small supporting area. In extreme cases, the pressure applied to an installed service component by a person's foot or chair leg may cause the service component to fall through the access panel into the space below the floor of an office.

It is an object of the present invention to provide a method of cutting an access panel and an access panel cutter which alleviate the above difficulties.

Accordingly, one aspect of the present invention provides a method of cutting an access panel on site to form a circular aperture in the panel at a desired location, comprising the steps of: supporting the panel on a portable

: panel holder; mounting on the panel holder a detachable cutting tool having a hollow, cylindrical cutting blade; adjusting the relative positions of the panel and cutting tool to position the cutting blade at a desired location of the panel; securing the panel in position with respect to the panel holder; and operating the cutting tool to cut the aperture in the panel.

Advantageously, the method comprises the step of placing the panel in a t selected position within a range of positions of the panel relative to the panel holder. Preferably, the method comprises the steps of: placing the cutting tool at a selected position within a range of positions along the length of an elongate support provided on the panel holder; and securing the cutting tool to the elongate support of the panel holder.

Conveniently, the method further comprises the steps of: providing a plurality of interchangeable cutting blades; and attaching a selected cutting blade to the cutting tool.

Another aspect of the present invention provides an access panel cutter for cutting a circular aperture in an access panel on site, comprising: a portable panel holder for supporting a panel; means for securing a panel held by the panel holder in position with respect to the panel holder; and a detachable cutting tool which has a hollow, cylindrical blade and which is mounted on the panel holder, the arrangement being such that the relative positions of the panel and cutting tool are adjustable to position the cutting blade at a desired location of a panel, whereby operation of the cutting tool cuts the aperture in the panel at the desired location.

( Advantageously, the panel holder serves to secure an access panel in a selected position within a range of positions of the panel relative to the panel holder. Preferably, the cutter further comprises one or more clamps to secure the access panel in position with respect to the panel holder.

Conveniently, the panel holder comprises an elongate support, the cutting tool being securable to the support at a selected position within a range of positions along the length of the elongate support.

Advantageously, the cutter further comprises securing means to secure the cutting tool to the elongate support of the panel holder.

Preferably, the cutter comprises a plurality of interchangeable cutting blades, for attachment to the cutting tool.

Conveniently, the cutting blade comprises a plurality of cutting teeth at a cutting end thereof, each of the cutting teeth having a cutting edge.

Advantageously, the cutting edge of a first cutting tooth is substantially straight when viewed in a cutting direction, the cutting edge of a second, adjacent cutting tooth has a bias to one side when viewed in a cutting direction, and the cutting edge of a third cutting tooth, adjacent the second cutting tooth, has a bias to the other side when viewed in a cutting direction.

Preferably, the cutting edge of each of the cutting teeth is separately formed and attached to the respective cutting tooth.

( s In order that the present invention may be more readily understood, embodiments thereof will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a panel holder for use with an access panel cutter embodying the present invention; Figure 2 shows an access panel cutter embodying the present invention; and Figure 3 shows a cutting blade for use with an access panel cutter embodying the present invention.

Referring firstly to Figure 1, a panel holder 1 generally comprises two parallel elongate beams 2, which are provided in spaced apart relation and joined together at one end by an elongate cross piece 3. The beams 2 and cross piece 3 are each generally rectangular in cross section, with major surfaces 2A of the beams 2 facing each other and being substantially perpendicular to those of the cross piece 3. The beams 2 and cross piece 3 are joined in such a way as to form a "U" shape.

A clamp support 4 extends between the other ends of the beams 2. The clamp support 4 comprises a platform which is secured to the minor surfaces 2B of the beams 2 at the other end of the beams 2, so that the major surfaces of the platform are perpendicular to those of the beams 2 and of the cross piece 3.

The clamp support 4 may be fixed to the beams 2 using screws or any other suitable means.

A cutting tool support 5 is also secured to the minor surfaces 2B of the beams 2 and spans the beams 2. The cutting tool support 5 comprises an elongate rectangular base 6 having low upstanding side walls 7, each of which runs the length of the elongate member 6 and is provided with a small inward-

facing flange 8 along the top edge thereof, the base 6 and the flanged side walls 7 thereby defining a slideway extending the length of the cutting tool support 5.

The cutting tool support 5 is parallel with the clamp support 4, and is located nearer to the cross piece 3 than to the clamp support 4. The cutting tool support 5 may also be fixed in place by screws, but any other suitable means may be used. Two flat, elongate supports 9 also extend between the beams 2. The supports 9 are affixed to the minor surfaces 2B of the beams 2 opposite the minor surfaces 2B to which the clamp support 4 and cutting tool support 5 are secured and are parallel to the clamp support 4 and cutting tool support 5. The supports 9 may be located approximately one third and two thirds of the way along the beams 2 respectively, but this arrangement is not critical and any suitable number and arrangement of supports 9 may be provided.

Each of the above components is preferably formed from a light, strong alloy, maintaining the strength of the panel holder 1 while allowing the panel holder 1 to be carried by an individual without excessive difficulty. An exception to this may be the walls 7 of the cutting tool support 5, which are preferably formed from a stronger material, for instance steel, for increased rigidity. A panel clamp 10 is provided on the clamp support 4. The panel clamp 10 may be of any suitable design, but in the depicted example comprises a

( toggle clamp having a handle 1 1 and clamping member 12, the handle 11 being operable to secure the clamping member 12 on or near the surface of one of the supports 9 in a clamping position, and to release the clamping member 12 from the support 9 in a released position.

As shown in Figure 2, a cutting tool 13 is removably mounted to the cutting tool support 5. The cutting tool 13 is provided with a base 14, which is substantially rectangular in shape and which is dimensioned to be slidably received in the slideway formed between the walls 7 of the cutting tool support 5. The inward-facing flanges 8 on the walls 7 extend over edge portions of the base 14 and retain the base 14 in the slideway, preventing the base 14 from being lifted off.

The base 14 may be introduced into the slideway of the cutting tool support 5 and moved along the slideway to adjust its position to any desired location along the length of the cutting tool support 5. Means are provided to secure the base 14, in its adjusted position, to the cutting tool support 5, and in the example depicted in Figure 1 the means comprise a series of threaded bolts 15 which extend through one of the walls 7 of the cutting tool support 5, and which may be rotated so as to advance through the walls 7 and press against the base 14, thereby clamping the base 14 in place.

Alternatively, or in addition to the threaded bolts 15, a cutting tool clamp 16 may be provided on the base, to clamp the base 14 to the cutting tool support The cutting tool 13 resembles a pillar drill, and is mounted so that the drill chuck 17 points vertically downwards, i.e. towards the supports 9. A

( handle 18 is provided to advance the drill chuck 17 towards the supports 9, the drill chuck 17 preferably being biased upwards, i.e. away from the supports 9.

With reference to Figure 3, a cutting blade 19 for use with the cutting tool 13 has a hollow, substantially cylindrical shape. An attachment end of the cylindrical cutting blade 19 is closed by an end plate (not shown), the end plate being provided with means for coupling the cutting blade 19 to the chuck 17 of the cutting tool 13. A cutting end 20 of the cutting blade 19 is provided with a plurality of cutting teeth 21, which extend from locations near the attachment end of the cutting tool 19 to the cutting end 20 of the cutting tool 19, in a direction slanted with respect to the central axis of the cylindrical shape of the cutting tool 19. The cutting teeth 21 are slanted such that, when the cutting tool 19 is rotated about the central axis of the cylindrical shape thereof in a cutting direction, the free ends of the teeth 21 are slanted towards the direction in which they advance.

Slots 22 are provided between the cutting teeth 21, these slots extending roughly half way along the length of the cutting teeth 21 from the free ends of the cutting teeth 21, to merge with respective flutes 23 which are formed between the roots of the cutting teeth 21 and assist in the removal of swarf during a cutting operation.

The cutting tips 24 of the cutting teeth 21 are advantageously provided with replaceable cutting edges, which may be formed, for example, from appropriately-shaped tungsten pieces welded on to the cutting tips 24. These tungsten pieces increase the effectiveness of the cutting blade 19, and are also cost effective, since the tungsten pieces may be replaced when worn to recondition the cutting blade 19 and avoid the need for the entire cutting blade 19 to be replaced.

In preferred embodiments of the present invention, the cutting blade 19 has a number of cutting teeth 21 that is a multiple of three. The cutting tip 24 of a first cutting tooth 21 of each set of three is substantially straight (i.e. lies in the plane of the cutting tooth 21) when viewed in a cutting direction. A second cutting tooth 21 immediately adjacent the first cutting tooth 21, has a bias to one side when viewed in a cutting direction, and a third cutting tooth 21 adjacent the second cutting tooth 21, has a bias in the other direction. This configuration of the cutting teeth 21 of the cutting blade 19 assists in the effective removal of material during the cutting of an aperture in an access panel. Preferably, the entire cutting blade 19, apart from the additional cutting tips 24, is formed from a single block of steel, or another suitable material.

Interchangeable cutting blades 19 of different dimensions may be provided for attachment to the cutting tool 13, for cutting apertures of different dimensions.

The most commonly required sizes of aperture are circular apertures having diameters of 127mm, 150mm, 171mm, 210mm and 22 lmm.

In use of the access panel cutter, an access panel is first placed on the supports 9 of the panel holder 1. The space defined by the walls 2 and cross piece 3 of the panel holder 1 is sufficiently large to accommodate the largest size of access panel that is commonly used, which is 750mm by 750rnm. The panel is placed at a desired location and is then secured in place against the supports 9 by the panel clamp 10.

A cutting tool 13 is attached to the cutting tool support 5. The base 14 of the cutting tool 13 is slid along the slideway of the cutting tool support 5 to a desired location, and is then secured in place by means discussed above.

It will be appreciated that, since the location of the panel in a direction parallel with the beams 2 of the panel holder 1 may be selected, and the location of the cutting tool 13 in a direction perpendicular to the beams 2 of the panel holder l may be selected, the access panel cutter may be arranged so that any point on the surface of the access panel is directly below the chuck 17 of the cutting tool 13.

A cutting blade l9 is attached to the chuck 17 of the cutting tool 13, and the cutting tool 13 is then advanced towards the access panel, using the handle 18, to cut a substantially circular aperture therein. The cutting tool 19 may optionally be provided with one or more holes in the top plate thereof, to allow the portion of the access panel that has been cut out by the cutting tool 19 to be released from the interior thereof.

It will be appreciated that the present invention provides an effective method of cutting a variety of dimensions of apertures in access panels on-site and at short notice. Cutters embodying the present invention may be portable and are capable of producing far higher quality results than can be obtained using a jig saw, and the present invention effectively alleviates the need for access panels to be returned to a factory or other off-site facility for high-

quality apertures to be cut therethrough.

In the present specification "comprises" means "includes or consists of"

and "comprising" means "including or consisting of".

The features disclosed in the foregoing description, or the following

claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process

for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS:

1. A method of cutting an access panel on site to form a circular aperture in the panel at a desired location, comprising the steps of: supporting the panel on a portable panel holder; mounting on the panel holder a detachable cutting tool having a hollow, cylindrical cutting blade; adjusting the relative positions of the panel and cutting tool to position the cutting blade at a desired location of the panel; securing the panel in position with respect to the panel holder; and operating the cutting tool to cut the aperture in the panel.

2. A method according to Claim 1, comprising the step of placing the panel

in a selected position within a range of positions of the panel relative to the panel holder.

3. A method according to Claim 1 or 2, comprising the steps of: placing the cutting tool at a selected position within a range of positions along the length of an elongate support provided on the panel holder; and securing the cutting tool to the elongate support of the panel holder.

4. A method according to any preceding claim, further comprising the steps of: providing a plurality of interchangeable cutting blades; and attaching a selected cutting blade to the cutting tool.

5. An access panel cutter for cutting a circular aperture in an access panel .. On site, compnsng:

( a portable panel holder for supporting a panel; means for securing a panel held by the panel holder in position with respect to the panel holder; and a detachable cutting tool which has a hollow, cylindrical blade and which is mounted on the panel holder, the arrangement being such that the relative positions of the panel and cutting tool are adjustable to position the cutting blade at a desired location of a panel, whereby operation of the cutting tool cuts the aperture in the panel at the desired location.

6. A cutter according to Claim 5, wherein the panel holder serves to secure an access panel in a selected position within a range of positions of the panel relative to the panel holder.

7. A cutter according to Claim 7, further comprising one or more clamps to secure the access panel in position with respect to the panel holder.

8. A cutter according to any one of Claims 5 to 7, wherein the panel holder comprises an elongate support, the cutting tool being securable to the support at a selected position within a range of positions along the length of the elongate support.

9. A cutter according to Claim 8, further comprising securing means to secure the cutting tool to the elongate support of the panel holder.

1 O. A cutter according to any one of Claims 5 to 9, comprising a plurality of interchangeable cutting blades, for attachment to the cutting tool.

11. A cutter according to any one of Claims 5 to 10, wherein the cutting blade comprises a plurality of cutting teeth at a cutting end thereof, each of the cutting teeth having a cutting edge.

12. A cutter according to Claim 11, wherein: the cutting edge of a first cutting tooth is substantially straight when viewed in a cutting direction; the cutting edge of a second, adjacent cutting tooth has a bias to one side when viewed in a cutting direction; and the cutting edge of a third cutting tooth, adjacent the second cutting tooth, has a bias to the other side when viewed in a cutting direction.

13. A cutter according to Claim 11 or 12, wherein the cutting edge of each of the cutting teeth is separately formed and attached to the respective cutting tooth.

14. A method substantially as hereinbefore described, with reference to the . accompanying drawings.

15. A cutter substantially as hereinbefore described, with reference to the . accompanying drawings.

16. Any novel feature or combination of features disclosed herein.