SPINDLE ACCESS DRILL The present invention relates to a hole saw that has applications in the plumbing industry in particular. A hole saw, also known as a hole cutter, is a circular saw, used in a drill, 5 router, or brace and bit. The saw consists of a metal cylinder, usually steel, mounted on an arbor. The cutting edge usually has either saw teeth formed in it or industrial diamonds embedded in it. To date, hole saws generally have a male arbor, which is designed to act as a centering mechanism to help the hole saw to bore without wandering. Alternatively, the arbor may carry a drill 10 bit to bore a centering hole. To date, in the construction and maintenance industry, and the plumbing industry more specifically, there has not been a simple means by which a tap spindle can be accessed to enable its removal for maintenance and/or replacement in the setting where the surrounding wall material encroaches 15 upon the spindle. Plumbers, handymen and construction and maintenance workers are often confronted by a situation whereby tiles or similar wall materials encroach sufficiently upon the tap spindle to prevent easy removal and they are forced to chip away at the surrounding material. The risk, here thereto, has been damage to said material beyond the extent that would 20 ordinarily be covered by the tap bell/flange and a subsequent unacceptable aesthetic outcome. It is an object of the present invention to overcome, or at least alleviate, one or more of the problems associated with the prior art. Accordingly, the present invention provides a hole saw including a central 25 female arbor. Preferably, the hole saw includes a cylinder having a cutting edge, said cylinder being mounted on a central female arbor, said arbor being capable of receiving a spindle, for example the spindle of a tap, which, in use, acts as a central axis around which the hole saw rotates.
By a 'central female arbor' is meant a mandrel, located approximately along the axis of the cylinder or hole saw and including a female recess at the end of the mandrel closest to the cutting edge of the cylinder or hole saw. Preferably, the recess of the female arbor contains or is lined with a bush (or 5 bushing), for example a nylon bush, a type of plain bearing to provide a bearing surface for the female arbor to rotate around the tap or other spindle. In use, the bush accepts the spindle and prevents or reduces damage to the spindle during the cutting process. Preferably, the internal diameter of the recess in the female arbor or bush (if a 10 bush is included) is such that, in use, it fits neatly over the spindle of the tap or other spindle, to reduce or minimize lateral movement of the arbor, while still allowing the arbor to rotate around the spindle. Preferably, the external diameter of the cylinder of the hole saw is such that, in use, it may be used to cut a hole in the material in which the tap or other 15 spindle is mounted, said hole being of a size that will subsequently be covered by the tap bell/flange or other housing that normally surrounds the spindle. Preferably, the cutting edge of the cylinder of the hole saw is diamond tipped, making it suitable for cutting materials such as ceramic, porcelain or glass tiles, or splash backs. 20 Preferably, the cylinder of the hole saw includes a base and is mounted on the female arbor by way of a thread in the base, so that the hole saw can be removed from the arbor, with said thread running such that the hole saw does not unscrew from the device when the drill is in action. Preferably, the cylinder of the hole saw includes a plurality of longitudinal 25 apertures, preferably elongated apertures such as slits, in the cylinder wall. These facilitate removal of the cut out material, for example by insertion of a screw driver or like instrument, which may be used to prize the material from the cylinder of the hole saw. Thus, the apertures facilitate removal from the cylinder of the material that has been taken from around the tap spindle. 30 Preferably the elongated apertures in the cylinder wall are approximately parallel to the axis of the cylinder, although they may also be slanted at an angle to said axis, In use, the hole saw of the present invention may be placed over a tap or other spindle, so that the spindle is received into the female arbor, which acts 5 as a central axis or guide. The hole saw may be attached to a tool such as a drill, router or brace and bit, such that the aforementioned device generates the rotational force to operate the hole saw, as is the case with hole saws currently in use. Thus, in use, rotation of the hole saw around the spindle enables the cutting edge of the hole saw to cut a hole in the material in which 10 the tap or other spindle is mounted. In this way, the hole saw may be used to enable careful and uniform removal of encroaching wall material (which may, for example, comprise ceramic tiles, porcelain, glass tiles, laminate, cement sheet, plaster or similar material) from around a tap or other spindle to allow access to said spindle, for example access to remove a tap spindle. 15 Preferably, the hole saw includes a drive shaft extending from the central arbor, which may be used to attach the hole saw to a tool such as a drill, router, or brace and bit. Preferably, the drive shaft of the hole saw has a cross section approximating a circle, with flattened sections or linear components (for example a hexagon or octagon) to allow adequate grip of the 20 drive shaft by the drill chuck or similar clamp. Applicant has surprisingly found that use of a female arbor stabilizes the hole saw upon the spindle, using the spindle as a central axis, and it is this feature that provides for a significant advancement in the industry whereby the tradesperson or handyman can perform the work quicker and with reduced 25 risk of inadvertent damage to the surrounding material. The invention may be better understood with reference to the illustrations of its embodiments. It should be understood, however, that the following description is illustrative only and should not be taken in any way as a restriction on the generality of the invention described above. 30 Figure 1 shows a side elevation of the device. Its overall length is usually in the order of 14 - 20 cm with the dimensions of the hole saw component being approximately 5 -6 cm long and approximately 4cm in diameter. The diagram demonstrates one of the plurality of apertures (into which a screw driver or like instrument can be inserted for easy removal of the material to be discarded). Dimensions provided are examples only and are by no means restrictive. 5 Figure 2 shows an end on view of the device with a view of the female arbor and the bush within it. Figure 3 shows the opposite end on view with the cross section of the drive shaft having an approximately circular configuration but with linear components to allow it to better grip in the chuck. 10 Figure 4 shows a perspective view demonstrating the internal workings of the device and the means by which the tap spindle neatly fits into the bush of the female arbor. Figure 5 is a photograph demonstrating how the device is put to use with a battery drill as the driver. 15