Keyboards for computers are well known. They comprise a base, a printed circuit board on the base, keys, cushion means for the keys, and a lid. The lid is generally secured in position to be a fixture. The cushion means for the keys are usually separate cushion members which are provided one for each key and which cushion the movement of the keys as they are depressed during use. A considerable problem with the known keyboards is the accumulation of dirt in the keyboards. The dirt may be in the form of dust, particles of food, bacteria and even scales from the skin of users of the keyboard. It is extremely difficult to clean the known keyboards. They are basically of a too complex construction to enable efficient cleaning by means of a vacuum cleaner and/or brushes.

It is an aim of the present invention to reduce the above mentioned problem.

Accordingly, in one non-limiting embodiment of the present invention there is provided a keyboard for a computer, which keyboard comprises a base, a printed circuit board on the base, keys, cushion means for the keys, and a lid, characterized in that the lid is constructed and adapted for being moved to an open position for enabling cleaning of the keyboard and for being moved to a closed condition after the cleaning for enabling use of the keyboard, characterized in that the cushion means is in the form of a sheet having integrally formed cushion members, and characterized in that the keyboard is such that when the lid is in the open position then the keys move with the lid, the cushion means remains over the printed circuit board, the printed circuit board is protected by the cushion means, and there are no loose cushion members to become displaced.

In the keyboard of the present invention, more efficient cleaning than in known comparable keyboards is allowed by virtue of the fact that the lid is constructed and adapted for being moved to the open position for enabling cleaning of the keyboard, and then for being moved to the closed position after the cleaning for enabling normal use of the keyboard. The lid is constructed for being moved between the open and the closed positions whenever the keyboard needs to be cleaned. This method of cleaning a keyboard in fact raises a potential problem in that, as mentioned above, the known keyboards have cushion means in the form of separate cushion members, one for each key of the keyboard. Thus if a known keyboard were simply modified to make its lid moveable between open and closed positions, then a further problem would arise in that the various separate cushion members could easily become displaced when the lid was moved to the open position because, as the lid is moved to the open position, it takes with it the keys and there is then nothing remaining to retain the cushion members in position. In such circumstances, cleaning of the keyboard would almost certainly dislodge the cushion members with a possibility that they could not be re-positioned in order to permit re-closure of the lid and proper functioning of the keyboard. A keyboard thus rendered non- functional could be such that it was no longer covered by its manufacturer's warranty. Even if the separate key members could be repositioned, the task would be time consuming and irritating, and therefore not cost effective.

The keyboard of the present invention overcomes this further problem by having the cushion means in the form of a sheet having integrally formed cushion members. Thus the cushion members all form part of a sheet and there are no individual cushion members in a keyboard of the present invention to become inadvertently displaced. Thus loss of cleaning time, misplacing of individual cushion members, invalidation of a maker's warranty, and damaging of the keyboard can all be avoided.

Preferably, the keyboard is one in which the lid forms a seal with the cushion means, when the lid is in the closed position. With such a formed seal, the ingress of dirt between the keys and on to the cushion means can be avoided.

Preferably, the lid and the cushion means have engaging sealing formations. Preferably, the engaging sealing formations are complementary male and female seals. The male and female seals can be positioned as desired, one on the lid and one on the cushion means.

Preferably, the lid is a hinged lid. The lid will normally be hinged to the base. The lid may be moveable between the open and closed positions by means other than hinges if desired.

The keyboard may be one in which the printed circuit board is able to be removed if required, for example if the printed circuit board should need replacing, refurbishing or upgrading. The printed circuit board may be removed from the top of the keyboard. Alternatively, the printed circuit board may be removed from the bottom of the keyboard, for example by sliding out from the keyboard when a release member is operated. The release member may be a release button which is pushed for the release condition.

The components of the keyboard of the present invention may be made from those materials currently employed in known keyboards. Thus, for example, the keys can be made of a hard moulded plastics material.

The known individual cushion means are made of a foam plastics material.

The sheet used in the keyboard of the present invention can be made of the same type of foamed plastics material.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 is a perspective view of a known keyboard with a lid in a closed position; Figure 2 is an exploded view of the keyboard of Figure 1 and illustrates the difficulty of efficiently cleaning the keyboard; Figure 3 is a perspective view of a first keyboard of the present invention, with its lid in a closed position; Figure 4 is a perspective view of a keyboard shown in Figure 3 but with its lid in an open position ; Figure 5 is a section through part of the keyboard shown in Figure 3; Figure 6 is a plan view of cushion means used in the keyboard shown in Figure 3; Figure 7 shows how the lid of the keyboard shown in Figure 3 is hinged to a base of the keyboard; and Figure 8 shows in exploded form part of a second keyboard of the present invention.

Referring to Figures 1 and 2, there is shown a keyboard 2 for a computer. The keyboard 2 comprises a base 4, a printed circuit board 6 on the base 4, and keys 8. The keyboard 2 also comprises cushion means 10 for the keys 8. The keyboard 2 still further comprises a lid 12.

The lid 12 is fixed in position by screws 14. The screws 14 are designed such that the lid 12 is intended to be fixed in position and not to be removed.

The cushion means 10 is formed by a plurality of separate cushion members 16. It will be seen that there is one cushion member 16 for each one of the keys 8. If the lid 12 were to be removed, it would automatically take the keys 8 with it. This would leave the separate cushion means 16 loosely assembled on the printed circuit board 6. Any movement of the keyboard 2, as would occur during a cleaning operation, would almost certainly cause the cushion members 16 to move from their required positions in which they accommodate the keys 8. The cushion members 16 would thus need to be re-positioned. If they were not correctly repositioned, the lid 12 could not be correctly replaced and/or the keyboard 2 would not function properly. A manufacturer's warranty may be invalidated, in addition to lost time and inconvenience caused by the non-functioning of the keyboard 2.

As can be seen from Figures 1 and 2, because the keyboard 2 is a complex thing having appreciable depth due to the various components formed by the base 4, the printed circuit board 6, the keys 8 and the cushions 10, it is extremely difficult efficiently to clean the keyboard 2. The use of a vacuum cleaner and/or a brush do not lead to good cleaning of the keyboard 2. It is not possible to get sufficiently far into the keyboard 2 through the gaps between the keys 8, with the vacuum and/or the brush, in order to pick up the very many different types of dirt that can be found in a keyboard 2, examples of such dirt being dust, pieces of food, pieces of paper, and various stationery articles.

Referring now to Figures 3-7, there is shown a keyboard 22 comprising a base 24, a printed circuit board 26 on the base 24, keys 28, cushion means 30 for the keys 28, and a lid 32.

The lid 32 is constructed and adapted for being moved to an open position as shown in Figure 4 for enabling cleaning of the keyboard 22. The lid 32 is also constructed and adapted for being moved back to a closed position as shown in Figure 3 after the cleaning, this being for enabling normal use of the keyboard 22. Thus, because the lid 12 can easily be moved to the open position, taking with it the keys 28, the keyboard 22 effectively is separated into two layers which can easily be cleaned. The cleaning can be effected with a vacuum cleaner and/or a brush as may be desired. Any other suitable and appropriate type of cleaning means may be employed.

The cushion means 30 is in the form of a sheet 34 having integrally formed cushion members 36. The sheet 34 with its integrally formed cushion members 36 is moulded from a foamed plastics material. Any suitable and appropriate material may be employed. When the lid 32 is in the open position, the sheet 34 remains on the printed circuit board 26.

There is no possibility of the cushion members 36 becoming displaced from their required position to receive the keys 28 when the lid 32 is closed. This is because the cushion members 36 are formed as an integral part of the sheet 34. Thus, during the cleaning, the cushion means 30 is able to protect the printed circuit board 26, and there are no loose cushion members like the cushion members 10 to become displaced. This in turn avoids difficulties in closing the lid 32, it avoids lost time and effort in repositioning misplaced cushion members, and it avoids invalidating a manufacturer's warranty due to self-inflicted damage.

The lid 32 has a peripheral rib 38 which fits in a peripheral groove 40 in the sheet 34. The rib 38 and the groove 40 form engaging sealing formations which enable the lid 32 to seal on to the cushion means 30 when the lid 32 is in the closed position. Thus dirt is prevented from getting on to the printed circuit board by passing between the cushion means 30 and the lid 32.

As best shown in Figure 6, the lid 32 is moveable between the open and the closed positions by being mounted on hinges 42. The hinges 42 enable the lid 32 to pivot about the base 24. Figure 6 also shows how the sheet 34 may be moulded with a cover 44 for additional circuits.

The keyboard 22 is such that the printed circuit board 26 is able to be removed, for example for replacing, refurbishing or upgrading, by being removed from the top of the keyboard 22 when the lid 32 is open. In Figure 8, there is shown part of a keyboard 52 having a base 54 and a printed circuit board 56, the keyboard 52 being such that the printed circuit board 56 is able to be removed from the bottom of the keyboard 56. More specifically, in Figure 8, the base 54 is shown twice so that the upper surface 58 of the base can be seen and also the lower surface 60 of the base can be seen. If the base 54 is removed, for example by rotating two locking arms (not shown) which rotate in apertures 62 in the base 54, then the base 54 can be removed from the remainder of the keyboard 52. This then exposes the underside 64 of the printed circuit board 56. The printed circuit board 56 can then be slid out from the remainder of the keyboard 52, for example by sliding in a frame part 66.

In the assembled condition, the base 54 fits inside a ridge 68. The locking arms employed in the apertures 62 can then be rotated to fit under the ridge 68 in order to hold everything together.

Keys for the keyboard 52 would be located on the surface 68.

The slideable removal of the keyboard may be effected when pushing a release member in the form of a release button. Any necessary circuit cables can also be arranged to slide out as may be required. The keyboard 52 still employs cushion means for the keys, and the illustrated base 54 may be a plate giving underneath access to the printed circuit board 56 in cases where it may be desirable to replace or refurbish the printed circuit board 56.

It is to be appreciated that the embodiments of the invention described above with reference to Figures 3-7 and to Figure 8 have been given by way of example only and that modifications may be effected. Thus, for example, whilst the cushion means 30 is preferably made from a latex material, other materials may be employed if desired. Also, the hinges 42 could be dispensed with, in which case the lid 32 could be a completely removable lid.