FIELD OF THE INVENTION

The present invention refers to a screw and unscrew system consisting of a screw, characterized in that the surface of its head bears a slot with a characteristic curved configuration, and of a screwdriver, the tip of which has a respectively configured profile. DESCRIPTION OF RELATED ART

Until today in the prior art, no similar screw object or system has been manufactured.

In particular the known prior art of screws and screwdrivers is related to conventional screws on the head of which a straight slot has been formed. A conventional screwdriver fits the slot, the tip of which is appropriately configured in order to fit the screw slot and by a turn of the screwdriver the fastening of the screw is achieved. Furthermore, by turning the screwdriver in the opposite direction, the unscrewing and removal of the screw is achieved. The above conventional screws and screwdrivers used, have the disadvantage that when the screw is tightened by the screwdriver the slot in the screw's head is distorted and as a consequence the screw is destroyed.

Moreover, and according to the prior art, the so-called "cross head screws" bear on their head a cross slot in order for better fitting of the respective screwdriver (cross-screwdriver) in the slot of the screw head and therefore, a safer screw to be achieved. The basic disadvantage of the cross head screws and the cross screwdrivers is that due to the cross shaped head slot, at the screw or unscrew of the screw by the respective screwdriver, some parts of the head slot, and in particular around the right angles created by the head slot of the screw, are tightened more than the others. As a consequence of this fact, when great pressure is exerted on the screw, the edges of the head slots of the screw are distorted. Said distortions become more and more intense after time and the screw is either substantially destroyed, or, in case the screw material is durable, the tip of the screwdriver is broken and effectively destroyed, and therefore, the purchase of a new screwdriver tip or screwdriver is required. Due to the above, the users prefer to buy expensive screwdriver

tips of particularly high endurance, a fact which increases the cost and at the same time does not resolve the problem of distorted screws.

SUMMARY OF THE INVENTION

All the above technical problems led to an attempt to find a solution, the result of which is the object of the present invention.

The proposed screw-screwdriver system, according to the present invention, is based on the mode of use of the cross head screw and the respective screwdriver, which ensures a reliable screw. In the system of the present invention, a particular configuration is provided, consisting of a curved X shape or equivalent on the head slot of the screw, in order for the slot not to comprise angles but completely curved surfaces. As a result the pressure exerted at the screw or unscrew by the screwdriver will be evenly distributed on the configured curved slot of the screw head and therefore, no distortions of the screw head will be created, the screw will remain intact, will fit the respective screwdriver and will have a longer duration of life. A screwdriver is used for the screw and unscrew of the screw, according to the present invention, the tip of which has a profile of a respective configuration, in order to completely fit the head slot of the screw, and also the screwdriver turns are more safe, stable and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be comprehensive to those skilled in the art, with reference to the accompanying drawings of the present specification, which indicatively show some industrially preferred embodiments of the present invention. In particular, figure 1 shows in perspective the screw and screwdriver tip system according to the present invention.

Figure 2 shows the screw head, with the curved configuration of the slot which the tip of the screwdriver of the system fits.

Figure 3, shows the appropriately configured screwdriver tip with a profile respective to the head slot of the screw system in order for the screw and unscrew of the screw system to be achieved.

The drawings show an example of the present invention. Hereinafter, same reference numbers of the main parts of the object refer to the corresponding

reference numbers of those parts in the accompanying drawings. The parts are not depicted to scale but simply in dimensions proportional to one another.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

According to the selected indicative embodiment of the invention, the invented screw 1 of the system, comprises a head 2, bearing a slot 3 configured in a shape of a curved X, in such a way that no angle is formed along the length of the slot 3. The invented screwdriver 4 of the system comprises a tip 5, the profile of which has an appropriate respective curved configuration in order to exclusively fit the slot 3 of head 2 of the screw 1 of the invented system. As a result at the screw or unscrew of the screw 1 by the screwdriver 4, the pressure is not exerted only to a specific part of the slot 3 of screw 1 , but on all parts of the curved slot 3, in order that any distortion created along the length of the slot 3 of head 2 of the screw 1 , leading to the destruction thereof, is prevented. For the same reasons, there is no danger of the breaking or distortion of the tip 5 of the screwdriver, regardless of the pressure exerted by the screwdriver 4.

It should also be noted that the object of the present invention should not be limited to the above described example. The accomplishment of this invention is also possible in other constructive ways, methods, fittings and machinery within the scope of the present specification.