Technical field The present invention relates to a staple for fastening an elongated object to a base, which staple comprise an arched bridge and legs and is designed for being connected to the base by a plate shaped driver, which driver acts on the outward directed surface of the bridge whereby the legs are forced into the base and whereby the arched bridge fastens the elongated object to the base.

State of the art Staples of the art described above are commonly found. Both the patent US 5,223, 675 and applicants application SE 0103645-8 shows such staples.

However, known staples possesses the drawbacks that when they are driven into the base theirs leg will tend to lean either forward or backward relative to the drivers working direction. The arched bridge will thereby correspondingly lean and thereby create an edge contact surface between the bridge and the elongated object, which may cause damage to the said object. Furthermore, a leaning staple gives either, when placed in a position where it is clearly exposed, the expression that the staple is not secure connected to the base or an inferior aesthetic appearance.

Problem Accordingly there exists a need to provide a staple which, when driven into the base, does not lean forward or backward relative to the drivers working direction.

Solution The present invention solves the problem said above with a staple of the art described in the introduction which is characterized in that the arched bridge comprises a notch which is situated in the outward directed surface and which notch engages with the driver when the driver drives the staple.

The present invention is further characterized in that the notch consists of a groove, which extends in the longitude direction of the bridge.

More further is the present invention characterized in that the groove is divided in more than one portion.

Further more further is the present invention characterized in that the groove is slightly broader than the driver is.

Additionally the present invention is characterized in that the groove is slightly conical with its broadest portion turned outwards.

Further additional the present invention is characterized in that the centre line of the groove is essentially in alignment to the centre line of the legs.

More further additional the present invention is characterized in that the depth and the breadth of the groove are essentially equal.

Additional further additional the present invention is characterized in that the notch consists of an aperture, which engages with a peg designed on the driver.

Finally, the present invention is characterized in that the staple confines only one leg.

Brief description of the figures The present invention will hereafter be described with reference to the accompanying figures in which; Fig. 1 shows known staples mounted to a base; Fig. 2 shows a staple according to the present invention, which fastens an elongated object to a base; Fig. 3 is a front view of a staple according to the present invention; Fig. 4 is a side view of a staple according to the present invention; Fig. 5 is a top view of a staple according to the present invention; Fig. 6-8 shows in front views a sequence of a driver, which drives a staple into a base; Fig. 9 is a cross sectional view from line B-B in Fig. 7; Fig. 10 is a to Fig. 4 corresponding view where the groove is conical; Fig. 11 is a to Fig. 3 corresponding view where the staple only comprises one leg; Fig. 12 is a to Fig. 5 corresponding view where the notch consists of an aperture, and Fig. 13 shows a driver which engages with a staple of the art shown in Fig. 12

Preferred embodiment Fig. 1 shows prior art staples. The figure shows a base 1 on which an elongated object 2 is fastened by staples 3. The staple has been driven by a blade shaped driver 4. The working direction of the driver is indicated by the arrow P. As is seen in the figure the legs 5 of the staple 3 to the left is driven into the base 1 in such a direction that the staple leans forward relative to the drivers working direction P and the staple to the right in the figure leans backwards relative to the said direction where forward is to the left in the figure.

Figure 2 shows a staple 103 according to the present invention, which fastens an elongated object 102 to a base 101. The elongated object 102 is shown as an electrical cable but the staple may be used to fasten any elongated object. The figure shows that the staple is driven into the base without any forward or backward leaning. Figure 3-5 shows in detail a staple in accordance with the present invention, which comprises a first leg 105 and a second leg 106. The legs are conjoined with an intermediate arched bridge 107. The legs 105 and 106 are essentially parallel. On the inner surface 108 of the bridge 107 are arranged projections 109 which secure that the cable does not move in the longitudinal direction but this feature is not part of the present invention and does therefore not be discussed further herein. On the outward directed surface 110 of the bridge, which surface, which will be described below, cooperates with the driver, is provided a notch 111, which is shown as a groove 112 which extends in the bridge longitudinal direction shown by the double arrow L in figure 5. The groove comprises a bottom 113 and walls 114. The dotted and dashed line A-A shows the longitudinally centre line of the legs 105 and 106, of which only the leg 105 is shown in figure 4. The line A-A does also show the longitudinally centre line of the groove 112 and as is shown the centre line of the groove is in alignment to the centre line of the legs. The grove centre line is most favorable situated when it is in alignment to the leg centre line as in figure 4 but the invention works satisfactorily if the groove centre line is slightly to the left or to the right relative to the leg centre line, figure 4.

With b is the breath of the groove indicated and with d is the depth indicated in figure 4. The groove functions especially well when the breath of the groove is essentially equal to the depth of the groove.

With reference to figure 6-8, is a staple 103 shown together with a driver 104, which drives the staple into a base 101, thereby fasten an object 102 to the base. The figures show that the driver 104 engages with the staple 103 and that the driver acts on the outward surface 110 of the bridge 107. Figure 9, which is a cross sectional view from line B-B in figure 7, clearly shows the engagement between the driver 104 and the groove 112. The thickness of the driver 104 is indicated by t and 115 indicate the driver sides. The driver has a working direction P 1 and the driver is preferably a driver included in a staple gun, which is not shown in the figures. Figure 9 does also disclose that the breadth of the groove is slightly broader than the thicknes of the driver 104 and which is obvious to the one skilled in the art the sides 115 will contact the walls 114 if the staple will tend to lean in either direction when the driver drives the staple. The driver will thereby drive the staple into the base without any possibilities for the staple to lean forward or backward relative to the drivers 104 working direction P 1.

Figure 10 shows a staple in which the groove is conical K with its broadest portion faced outward. The conical shape makes it easier for the driver to enter the groove. However, the conical shape does not alter the function of the staple from the staple described above.

Figure 11 shows a staple 203 with only one leg 205. The function of the invention is the same if the staple has one or two leg but a staple with one leg is easier to remove from a base than one with two legs. A staple with one leg may be fastened to a smaller base than one with two legs since there need not to be space for more than one leg.

Figure 12 shows a staple 303, which comprises a notch 311, which consists of an aperture 316. Figure 13 shows a driver 304, which has a peg 317, which engages with the aperture 316. This arrangement works in the same way as is described above and the arrangement secure that the staple does not lean forward or backward relative to the working direction of the driver.

The figures shows the groove as one continues groove which extends along the whole bridge but the one skilled in the art does easily understand that the groove may be divided into separate portions or extend only along parts of the bridge.