Technical Field of the Invention

This invention relates to a waterproof casing, in particular a waterproof casing for a powertool.

Background to the Invention

In some, situations such as marine operations it is desirable to be able to operate power tools underwater, for example for underwater drilling operations or tightening/loosening of screws underwater.

Known powertools capable of underwater operation include pneumatic and hydraulic drills, however these can be unwieldy and require hoses or leads going back up to the surface in order to operate. Additionally, it is not normally possible to operate a powertool underwater unless the powertool has been specifically designed for such use.

A further consideration is the amount of noise created by the powertool, which in the case of pneumatic and hydraulic drills can be considerable. Operating time is also important, which can be quite limited in the case of pneumatic drills that are driven by air from a diver's air cylinder.

It is therefore an aim of the invention to improve upon the known art.

Summary of the Invention

According to an embodiment of the invention, there is provided a waterproof casing for a powertool, the powertool comprising a drive output for interchangeably connecting various tools. The waterproof casing comprises a waterproof enclosure for enclosing the powertool, and an interface tool for connecting to the drive output. The interface tool comprises a sealing surface for sealing against an aperture in the waterproof enclosure, a tool fitting for connecting a tool, and a shaft for supplying force from the rotating drive output to the tool fitting.

Advantageously, the waterproof casing may be retrofitted to a commercially available powertool to convert the standard powertool for underwater use. However, the waterproof casing may, instead, be part of the powertool design, rather than a retro-fitted item. The waterproof casing may, for example, be waterproof up to a depth of at least 2m, or at least 5m, or at least 10m in water.

The tool fitting may be provided at one end of the shaft for connecting to the tool, and a powertool fitting may be provided at an opposite end of the shaft for connecting to the drive output of the powertool. Then, preferably the sealing surface is located between the tool fitting and the powertool fitting so that the powertool fitting remains dry during underwater use and the tool fitting is exposed for connecting the tool. The tool fitting may enable a variety of different tools to be interchangeably connected to the tool fitting. The tools to which the drive output of the powertool is capable of connecting to may or may not be the same tools to which the tool fitting of the interface tool is capable of connecting.

The drive output of the powertool may be a rotating drive output, and the shaft of the interface tool may be configured to supply rotational force from the rotating drive output to the tool fitting. For example, the powertool may be a drill or a screwdriver, rather than a purely reciprocating powertool such as a chisel.

Advantageously, the interface tool may further comprise a rotatable bearing mounted around the shaft, the rotatable bearing at least partly providing the sealing surface. The use of a rotatable bearing means that the aperture of the waterproof enclosure can seal against a stationary sealing surface of the rotatable bearing even whilst the shaft is rotating, improving the seal between the aperture and the sealing surface. The stationary sealing surface may for example be an outer ring of the rotatable bearing.

The shaft may comprise a lower diameter portion providing the powertool fitting and a higher diameter portion providing the tool fitting, the rotatable bearing being slid over the lower diameter portion to rest against the higher diameter portion. A collar may be fitted to the lower diameter portion of the shaft to fix the rotatable bearing in place between the collar and the higher diameter portion, thereby providing a simple method of constructing the interface tool.

The sealing surface may further comprise a rotating sealing surface in addition to the stationary sealing surface that is provided by the rotating bearing. The rotating sealing surface may be a portion of the shaft that has a circular cross-section and that rotates relative to the powertool and therefore the waterproof enclosure during use. The aperture of the waterproof enclosure may be arranged to seal against the rotating sealing surface in addition to the stationary sealing surface to improve the overall sealing. The stationary sealing surface that is provided by the rotating bearing can also help stabilise the aperture and prevent it from moving in directions perpendicular to the shaft, thereby improving the sealing between the aperture and the rotating sealing surface.

Preferably, the rotating sealing surface is located closer to the tool fitting than the stationary sealing surface. Then, the rotating sealing surface helps limit/prevent water from reaching the rotatable bearing, prolonging the life of the rotatable bearing. The aperture of the waterproof enclosure may comprise a skirting for pressing against the rotating sealing surface under external water pressure. Accordingly, when assembling the waterproof casing the tool fitting of the interface tool may be pushed into and through the aperture in a direction from inside the waterproof enclosure to outside the waterproof enclosure:

The rotatable bearing is preferably a sealed bearing to help prevent water ingress, for example a sealed cartridge bearing. The rotatable bearing may be a rolling element bearing, for example a ball bearing or a roller bearing. Advantageously, the aperture of the waterproof enclosure may be formed through a rigid portion of the waterproof enclosure, and the rigid portion may provide a friction fit against the stationary sealing surface of the rotatable bearing. The friction fit provides good sealing between the stationary sealing surface and the rigid portion, particularly when grease is applied between them, and helps hold the stationary sealing surface stationary when the shaft is rotated. The stationary sealing surface of the rotatable bearing allows pressure to be applied to the stationary sealing surface to provide a good seal without the pressure causing significant friction/drag against the rotation of the shaft.

The rigid portion may comprise rotational fixing means that help fix the rotational position of the rigid portion relative to the powertool, in order to counter any tendency of the rigid portion to rotate due to rotational forces transmitted through the rotatable bearing when the shaft rotates. A convenient and easily adaptable rotational fixing means comprises extendable protrusions which are extendable towards one another to grip the powertool.

Advantageously, the waterproof casing may comprise a flexible sock portion for surrounding the powertool. The flexibility of the sock enables the sock to be easily placed around the powertool, and enables an operator to operate controls on the powertool through the sock. The flexible sock portion may extend from the rigid portion, and may be permanently fixed to the rigid portion so that the sock can be turned inside-out when fitting the interface tool through the aperture of the rigid portion, and then turned back the right way again over the powertool to cover the powertool. The waterproof enclosure may further comprise a rigid base portion around which the flexible sock can be stretched to seal the open end of the sock after it has been turned back the. right way. O-Rings may be provided for gripping the open end of the sock around the rigid base portion.

According to another embodiment of the invention, there is provided a powertool system comprising a powertool and the waterproof casing. The waterproof casing is for converting the powertool so that the powertool is suitable for use underwater. The powertool comprises a drive output for interchangeably connecting various tools.

Preferably, the powertool is battery operated so that the powertool is not tethered by any external leads. The powertool may for example be a battery powered drill, or a battery powered screwdriver. Preferably, in the case where the waterproof enclosure comprises the flexible sock and the rigid base portion, the waterproof casing is arranged so that the rigid base portion covers a battery of the powertool, so that only the rigid base portion of the waterproof enclosure needs to be removed from the powertool in order to change the battery of the powertool.

An additional protective sleeve, for example made from neoprene, can be placed over the flexible sock around the main body of the powertool without affecting the operation of controls through the flexible sock. This additional sleeve provides increased abrasion resistance, thereby providing a more rugged powertool.

Brief Description of the Drawings

Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Fig. 1 shows a schematic diagram of a known powertool;

Fig. 2 shows a schematic diagram of the known powertool when converted for underwater use by a waterproof casing according to an embodiment of the invention; and

Fig. 3 shows an enlarged schematic diagram of a portion of the schematic diagram of Fig. 2.

The drawings are purely illustrative and are not to scale. Same or similar reference signs denote same or similar features.

Detailed Description

The schematic diagram of Fig. 1 shows a known powertool, in particular a known battery operated drill 100. The battery operated drill 100 has a handle portion 120 for a user to hold the drill. The handle 120 is arranged between a main body 110 and a battery portion 130. The battery portion 130 comprises a battery holder and a battery connected to the battery holder for powering the drill. The main body 110 has a drill chuck 115 protruding therefrom, and the drill chuck 115 is shown gripping a drill tool 150. A trigger control 125 is mounted on the handle 120 for the user to control the rotation speed of the drill chuck and drill tool. The drill chuck provides a rotating drive output that is capable of interchangeably accepting various different tools. The drill chuck may be capable of accepting screwdriver tools as well as drill tools, for example if the trigger control 125 allows sufficiently precise slow-speed control of the drill chuck rotation speed.

The schematic diagram of Fig. 2 shows the battery operated drill 100 when converted for underwater use by a waterproof casing according to an embodiment of the invention. The waterproof casing comprises an interface tool 200 to interface between the drill chuck 115 and the drill tool 150, and a waterproof enclosure formed of a rigid portion 210 to create a waterproof seal against a sealing surface of the interface tool 200, a flexible sock 220 extending from the rigid portion 210 and surrounding the drill 100, and a rigid base portion 230 that closes the end of the flexible sock opposite the end of the flexible sock having the rigid portion 210. The rigid base portion 230 is positioned over the battery portion 130, and the rigid base portion is secured to the flexible sock by an O-ring 225 extending around the flexible sock and pressing the sock against an outside of the rigid base portion 230.

The rigid portion 210 in this embodiment has a cylindrical shape that fits around the drill chuck 115 and main drill body 110, and has an aperture aligned with the axis of the cylindrical shape that allows the interface tool to pass through and seal against the sides of the aperture. The cylindrical shape has a circular cross-section, although in alternate embodiments other cross-sectional shapes may be used.

The rigid base portion 230 in this embodiment is formed as a cylinder with a one open end and one closed end i.e. as a cup shape. The cylinder has a circular cross-section, although in alternate embodiments other cross-sectional shapes may be used.

One end of the flexible sock 220 is permanently fixed around the cylindrical shape of the rigid portion 210, and the other end of the flexible sock 220 is removably fixed around the cylindrical shape of the rigid base portion 230 by the O-ring 225. The rigid base portion 230 comprises a small ring-shaped groove (not visible in Figs) around the circumference of the rigid base portion 230, the O-ring 225 resting around the groove and forcing the flexible sock 220 into the groove. ^' \ The rigid portion 210 and the rigid base portion 230 are for example formed of a rigid plastics material such as nylon, and the flexible sock is for example made of latex or a -flexible plastics material.

In order to fit the waterproof casing to the drill 100, firstly the interface tool 200 is fixed into the drill chuck 115, then the. rigid portion 210 is slid over the interface tool 200 with an end of the interface tool 200 passing through an aperture of the rigid portion 210 until a waterproof seal therebetween is made, then the flexible sock 220 is pulled over the main body and handle of the drill 100, and finally the rigid base portion 230 is fixed to the flexible sock to close the flexible sock adjacent the battery portion 130. The rigid portion 210 comprises extendable protrusions in the form of screws 215 and 216, which can be screwed inwardly towards the main body 110 of the drill 100 to grip against the main body 110 and help hold the rigid portion 210 in place relative to the drill 100.

ThQn, a user may attach the drill tool 150 (or any other suitable tool) to the interface tool 200, and submerse the drill underwater and operate the drill by pressing the trigger 125 through the flexible sock. If the drill requires a battery change, then the rigid base portion 230 can be separated from the flexible sock 220 to allow the battery to be changed without having to remove the whole of the underwater casing from the drill 100.

The waterproof casing will now be described in more detail with reference to the enlarged schematic diagram of Fig. 3. The rigid portion 210 is provided with screw threads within which the screws 215 and 216 can be screwed towards the main body 110, the screws haying screw heads 217 and 218 for extending and retracting the screws to respectively attach or detach the rigid portion 210 from the main body 110.

The rigid portion 210 has a cylindrical shape with a narrower aperture 212 at one end, and a relatively wider aperture 211 next to the narrower aperture 212. The narrower aperture is fitted with a skirt 213 that is attached around the narrower aperture, and which is free to flex therefrom. < ^■

The narrower aperture 211 of the rigid portion 210 is closer to an end of the rigid portion than the wider aperture 212, so that the rigid portion 210 can be slid over the interface tool 200 after the interface tool 200 has already been secured in the drill chuck. The interface tool 200 comprises a shaft having a lower diameter portion 310 and a relatively larger diameter portion 340. The lower diameter portion 310 provides a powertool fitting that is secured in the drill chuck 115, and the larger diameter portion 340 comprises a tool fitting that secures the drill tool 150.

The interface tool 200 also comprises a rotatable bearing 330 that is fitted around the lower diameter portion 310. The rotatable bearing 330 is held in place against the larger diameter portion 340 by a collar 320 that is fixed to the lower diameter portion 310, for example by a grub screw. The rotatable bearing means that the shaft 310, 340 is free to rotate within the rotatable bearing whilst an outer surface around the circumference of the rotatable bearing remains stationary. Accordingly, the outer surface provides a stationary sealing surface 335. The outer surface (stationary sealing surface 335) may be formed by an outer ring of the rotatable bearing.

The stationary sealing surface 335 provides a friction fit between the wider aperture 211 of the rigid portion 210 and the rotatable bearing 330, the friction fit holding the stationary sealing surface 335 stationary against the inside surface of the wider aperture 211 as the shaft 310, 340 rotates within the rotatable bearing. The friction fit maybe provided with grease to help the stationary sealing surface 335 slide inside of the wider aperture 211, and/or to improve the waterproofing of the seal created by the friction fit between the stationary sealing surface 335 and the inside of the wider aperture 211..

An outer surface of the larger diameter portion 340 has a circular cross-section and provides a rotating sealing surface 345 for the skirt 213 of the rigid portion 210 to seal against. The skirt 213 is preferably greased to improve the seal against the rotating sealing surface 345. The sealing surface 345 is termed a rotating sealing surface since it rotates when the drill is operated.

Since the interface tool 200 can only be fitted into the rigid portion 210 at the correct orientation by sliding the interface tool into the rigid portion from the direction of the wider aperture 211, the skirt will always be pushed by the shaft 340 in a direction away from the rotatable bearing 335, and towards the external environment. Therefore, when the drill is immersed underwater, the water pressure tends to force the skirt 213 against the rotating sealing surface 345 to help prevent ingress of water towards the rotatable bearing.

The tool fitting in this embodiment comprises an elongate aperture along the axis of the larger diameter portion 340, the drill tool 150 being inserted into the elongate aperture and being rotationally fixed by corresponding longitudinal grooves/protrusions in the drill tool and elongate aperture. Alternatively, the tool fitting may comprise grub screw(s) for gripping the drill tool 150 in the elongate aperture. Other types of tool fittings are clearly also possible, for example drill chucks.

The waterproof enclosure of the described embodiment comprises a rigid portion, a flexible sock portion extending from the rigid portion, and a rigid base portion that is repeatedly removable and connectable to the flexible sock portion, although other configurations of the waterproof enclosure will also be apparent, to the skilled person without departing from the scope of the appended claims. For example, the waterproof enclosure could be an entirely rigid enclosure that is snap-fitted around the powertool. The entirely rigid enclosure could support buttons or triggers for controlling the powertool.

Although the described embodiment relates to a battery powered drill tool, the waterproof casing could clearly also be applied to other types of powertools to allow underwater use, for example to battery powered screwdrivers. Various other embodiments of the invention falling within the scope of the appended claims will also be apparent to those skilled in the art.

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