EP1974865A1

EP1974865A1 - Device for holding a nail during its insertion into a solid object

Info

Publication number: EP1974865A1
Application number: EP08102083A
Authority: EP
Inventors: Margherita Doriguzzi Bozzo; Benedetta Doriguzzi Bozzo
Original assignee: Metrica SpA
Current assignee: Metrica SpA
Priority date: 2007-03-30
Filing date: 2008-02-27
Publication date: 2008-10-01
Also published as: ITMI20070110U1

Abstract

A device (100) for holding a nail during its insertion into a surface (S) of a solid object comprises a body (1) presenting at least one V-shaped seat (8, 80) the walls of which are defined by magnetic means (20, 21; 92, 93), said seat (8, 80) having a slot (9, 90) open at its ends (9A, 9B) and presenting a longitudinal axis (K) perpendicular to a plane of a base face (2) of said body (1), said magnetic means (20, 21) retaining the nail during its insertion; the magnetic retention means present on the adjacent walls (16, 17) of the V-shaped seat (8) are mutually independent elements (20, 21; 92, 93) presenting opposing polarities, the positive polarity of a first magnetic element hence opposing the negative polarity of the second.

Description

The present invention relates to a device for holding a nail during its insertion into a solid object, such as a wall of a building or a wooden block, in accordance with the introduction to the main claim.
It is known from experience how difficult it is to insert a nail in a perpendicular direction into a surface of said solid object, done generally by a hammer. In this respect it often happens that the nail penetrates at an angle other than 90° into the surface, making it possible for the nail to bend. To prevent this, the nail is usually held with the fingers until it has been completely inserted into said body. However this often means that the fingers are struck by the hammer, a drawback that arises especially if the nail is short or has a length similar to the thickness of the fingers. This drawback mainly arises in a domestic or otherwise non-professional environment.
Various solutions are known for solving the problem of both positioning the nail along an axis perpendicular to the surface into which the nail is to be driven, and of personal safety aimed at preventing the user from injuring the fingers with the hammer. However these solutions do not in reality properly solve said problems.
For example, JP2002154070 describes a device of the stated type having a substantially L-shaped body with a flat base and presenting on one side a slot perpendicular to the base. In this slot a magnet is present defining a flat wall of the slot; in the slot a nail is then placed for its insertion into a surface on which the known device rests via its flat base. Although this solution enables the nail to be held during its insertion into said surface without the nail having to be touched by the fingers (the user acting directly on the body of the known device), it does not ensure that the nail is perfectly perpendicular to said surface. This is due to the fact that as the magnet present has a flat face, the nail can incline on it during hammering even though remaining rigid with the magnet, as the magnetic circuit generated by the magnet closes along the nail shank, whatever its inclination.
US7100475 describes an elongate device presenting at one end a V-shaped portion or guide inside which a magnet is positioned having a flat face perpendicular to the longitudinal axis of the device. At this portion a flat face is present which lies below the device and is intended to rest on the surface into which a nail is to be inserted. During this insertion, this nail is held by the device via the V-shaped guide and in particular by the magnet present in it.
In this known solution the V-shaped guide is spaced from said surface.
As in the case of the Japanese text, the solution described in the United States patent does not ensure that the nail is positioned and retained in a direction exactly perpendicular to the surface into which it is to be inserted. In this respect, if the nail is thin with a diameter less than the opening of the V-shaped guide, it can position itself inclined to the surface even though remaining adhering to the flat magnetic face which acts as a fulcrum, as is explicitly stated in the same prior text. This prevents the nail from finding within the V-shaped guide a specific resting point able to ensure its perpendicularity to said surface.
If instead the nail has a diameter greater than the width of the V-shaped guide, it lies distant from the flat face of the magnet and does not adhere thereto but remains initially suspended between the two arms of the guide. For this reason and also because this latter is distant from the aforesaid surface, the nail is unable to assume a position perpendicular to this surface.
US4967623 describes a device presenting a gripping element supporting, at the end of a rod, a magnetic element presenting a V-shaped slot or guide arranged to support a nail during its insertion into a surface of a solid object. The rod can be replaced by a spring. According to this prior document, the gripping element has a size considerably greater than that of the magnetic element and interferes with the resting of this latter on said surface, making it impossible to use this known device for short nails (the use of which frequently results in injury to the non-professional or non-expert user).
Said problem arises both whether the magnetic element is supported by a rigid rod or is supported by a spiral spring. In both cases the nail can position itself with its axis inclined to the longitudinal axis of the slot because its conical point is attracted by the magnetic element; this obviously makes it impossible to obtain specific perpendicularity to the surface into which the nail is to be inserted.
US4667742 describes a nail support presenting a magnetic head pivoted to the end of a support handle and presenting a V-shaped slot, generally perpendicular to the end part of the handle. The head consists of a single magnet (V-shaped in its central part) disposed between two plates. Above it there moves a spring-operated hammer rigid with said support handle.
The base of the head is of small dimensions, and positioning the nail perpendicular to the surface during hammering can again be precarious and awkward as the head is located at the end of an elongate (curved) handle. The absence of a gripping element positioned directly opposite the base of the head makes it difficult to position and maintain the known device at the point where the nail is to be inserted into the solid object.
Again in this case, as in the case of the previously cited prior United Stated patent, the magnetic faces of the head which define the slot of this latter rest on the surface though which the nail is to be inserted, with consequent possible inclination of the nail to the longitudinal axis of the slot because of the attraction of its conical end part towards said faces.
Moreover, in that prior patent the magnetic head is described as traversed by a hole containing a pin for its fixing to the handle, this being a disadvantage because it subtracts magnetic mass from the head. Consequently, this latter must be of relatively large size, hence precluding the possibility of using this known device with short nails.
With reference to the latter two cited prior patents, they have in common the fact that the V-shaped guide or slot in which a nail is placed is provided directly in a magnet, which means that the weakest lines of force of the magnetic flux pass through the vertex of the slot (the term "vertex" being used for brevity as the plan projection of the straight line crossing the two planes containing the sides or side faces of the V), whereas they are most intense in proximity to the free ends of the faces of the V-shaped slot (and especially of the plates, if present, associated with them). Consequently, the nail placed in the slot could tend to lie adherent to only one of the two faces of this latter, with the resultant impossibility of ensuring that the nail lies with its longitudinal axis exactly parallel to the longitudinal axis of the slot, with consequent inclination of the nail to the surface in which it is inserted.
In other words, in all the aforestated patents, the magnetic element essentially performs the function of retaining the nail against its accidental fall, but does not automatically ensure with certainty that during hammering it remains positioned and retained parallel to the longitudinal axis of the slot, as the magnetic flux linkage through the nail when positioned in proximity to the slot is less effective.
An object of the present invention is to provide a device for holding a nail during its insertion through a surface of a solid object which represents an improvement over the known devices.
A particular object of the invention is to provide a device of the aforestated type which is able to ensure that the nail is correctly positioned perpendicular to the surface into which it is to be inserted, and to ensure that it remains correctly guided during hammering.
A further object of the invention is to provide a device of the stated type which is economical, of simple production and of easy and intuitive use, even for an operator totally inexpert in driving a nail perpendicular to the surface, without any possibility of error, with total reliability, and without the risk of injury with the hammer, even when using nails of short length.
These and other objects which will be apparent to the expert of the art are attained by a device in accordance with the accompanying claims.
The present invention will be more apparent from the accompanying drawings, which are provided by way of non-limiting example and in which:

Figure 1 is a plan view of a first embodiment of the invention;
Figure 2 is a section on the line 2-2 of Figure 1;
Figure 3 is a view in the direction of the arrow A of Figure 1;
Figure 4 is a view from above or plan view of a second embodiment of the invention;
Figure 5 is a side view of the device of Figure 4;
Figure 6 is a section on the line VI-VI of Figure 7 through a further embodiment of the invention;
Figure 7 is a view from above of the further embodiment of the invention;
Figure 8 is a view from above of a further embodiment of the invention;
Figure 9 is a view in the direction of the arrow B of Figure 8; and
Figure 10 is a side view of a part of the embodiment of the invention shown in Figure 8.

With reference to Figures 1-3, these show a device 100 according to the invention. It comprises a body 1 presenting a resting base 2 allowing said body to be able to be rested on an at least locally flat surface S (see Figure 3) into which a nail is to be inserted. This surface can be of any type such as a wall, a wooden plank or the like. The body 1 comprises an upper face 3 opposite the surface or base 2 and from which an element 4 rises to act as a gripping element for the device 100 during the insertion of a nail into said surface.
The body 1, shown in the figure as of substantially trapezoidal shape when viewed in plan, comprises a first end 5 and a second end 6. At the second end 6 a portion 8 is present to act as a seat or gripping and holding portion for the nail during its insertion into said surface.
More specifically, the portion 8 presents a V-shaped slot 9, i.e. a slot presenting opposing sides 16, 17 which converge towards a common vertex 19. Said sides are defined by independent flat magnets 20, 21 fixed in any known manner to the body 1, and presenting opposing polarities disposed such that the positive pole of the magnet 20 is faced by the negative pole of the magnet 21 and vice versa (or such that the magnet 20 presents its positive pole facing the vertex 19 of the slot and the magnet 21 presents its negative pole facing said vertex).
The longitudinal axis K of the slot 9 is perfectly perpendicular to the surface or plane P on which the resting base 2 of the body lies. The portion 8 is spaced from this plane P by a short distance d equal approximately to the height of the conical point of an average length nail intended to be positioned within this slot for its insertion into the surface S of the solid object by hammering.
The slot 9 is therefore open on both the sides 9A and 9B corresponding to the base 2 and the face 3 respectively. This enables the nail to move freely within the portion 8.
The use of the aforedescribed device for inserting a nail into a solid object is simple and intuitive. After resting the base 2 on the surface S of the object, a nail is located within the slot 9 of the portion 8 with its point facing said surface. The nail is attracted by the magnetic field, generated by the (opposing) poles of the two magnets, towards the vertex 19 of the slot and is held in a direction perpendicular to its longitudinal axis. On being struck by the hammer, the nail sides along the longitudinal axis K of the slot 9 and is driven into the surface S in a direction perpendicular to this latter by the guide provided by the slot. The nail is retained in this position by the magnets while the operator's fingers grip the gripping element of the body 1, which hence remain in a safe position sufficiently far from the hammer head, so avoiding the danger of accidental injury to the fingers.
In contrast to the previously cited prior patents, the proposed solution presents the advantage of a more effective "magnetic" slot 9 along the entire extension of its side faces 16 and 17 as far as the slot vertex 19, with a force of attraction which gradually increases the more the nail approaches the vertex, this having been verified by experience. This is because of the presence of the two independent magnets 20 and 21 of opposing polarity, as aforedescribed. The device 100 provides the certainty that the nail, of any size, is attracted towards the vertex 19 of the slot 9 without the need for voluntary action by the operator, and enables the nail to be firmly held always in a position perpend icular to the surface of the object into which it is to be inserted. The nail always remains rigorously adhering to both magnetic faces of the slot 9 even during translational movement under the percussion force of the hammer (hence ensuring its penetration perpendicular to the surface); this happens by virtue of the fact that the lines of magnetic force generated between the opposing faces become disposed un such a manner as to always attract the nail towards the vertex 19 of the slot 9, while enabling said nail to slide along said faces by hammering.
Moreover, by virtue of the distance d existing between the plane P and the end 9A of the slot 9, no or only very limited magnetic attraction is exerted on the usual conical point of the nail at the commencement of hammering, so avoiding any action tending to rotate the nail within the portion 8 of the device 100, which rotation would incline the nail on the surface into which it is to be inserted. The distance d separating the slot from the plane P also serves to prevent any burrs present on the point of the nail from preventing it from lying parallel to the axis K of the slot 9.
Once the nail has penetrated into said surface, the user can remove the device 100 by moving it laterally from the nail and overcoming the magnetic force of the magnets 20 and 21, as the nail is already partially inserted securely into said surface.
The slot length along the axis K is calculated in relation to the length of the nails to be hammered. It must be such as to retain the nail in a position perpendicular to the surface into which it is to be inserted, but be sufficiently limited to enable small-dimension nails to penetrate sufficiently into said surface before the usual nail head comes into contact with the end 9B of the portion 8.
Figures 4 and 5, in which parts equal to those already described are indicated by the same reference numerals. show a device 100 presenting a first portion 8 and a second portion 80, these being conceptually identical by the presence of opposing polarity magnets thereon, to respectively contain nails of different dimensions and diameters during their insertion into the surface of a rigid object. Each portion 8 and 80 has a different length from that of the other portion (for example 12-13 mm and 4-5 mm respectively) in order to be able to hold at least most of the different nail types usually used, during their insertion into the surface of the solid object. Moreover, as generally the shortest nails are also the thinnest, the slots 9 and 90 of the portions 8 and 80, again V-shaped and defined by independent magnets 20, 21 and 92, 93 and with opposing polarities, have different opening angles. Specifically, the shorter slot (90) presents a narrower angle (for example 30°-40°), whereas the longer slot (9) presents a wider angle (80°-90°).
A further embodiment is shown in Figures 6 and 7 in which parts corresponding to those already described are indicated by the same reference numerals. In these figures, the device 100 comprises a body 1 to rest, via feet 110, 120 and 130, on the surface S into which a nail is to be inserted. From the body 1, in proximity to a lower part 1A thereof, an arm 190 projects carrying at its end a V-shaped portion 8 for containing a nail during its hammering into the surface S. Again in this case the portion 8 presents a slot 9 with its axis perpendicular to the surface S and bounded by sides 16, 17 defined by independent magnets 20, 21 positioned with opposing polarities (similar to that described for the preceding figures). The slot 9 is again freely open at its two ends, with the end 9A spaced from the surface S.
A final embodiment of the invention is described in Figures 8-10 in which parts corresponding to those of the already described figures are indicated by the same reference numerals. In this figure, the device 100 has a shape very similar to that of the device of Figures 1-3, but comprises at the portion 8 an elastic element 300 for retaining the nail within the slot 9 of said portion 8. The elastic element 300 is defined by a thin blade of hardened steel and is shaped as a hairpin spring by presenting a first end portion 66 bent through 180°, a protuberance 62 complementary to the slot 9 and possibly provided with a small flat face at its vertex to corresponding with the nail, and a second end portion 74 extending beyond the width of the device 100 to enable it to be raised manually for positioning the nail or for its release after being driven into the surface S.
By resting the nail in the slot 9 after lifting the elastic element 30 and then releasing this latter, the nail is held very rigidly in a position perpendicular to the surface S.
A preferred embodiment of the invention has been described; others are however possible such as one in which each magnet presents its two polarities in the faces 16 and 17 of the slot 9 as shown in Figure 3 (the polarities of one magnet opposing those of the other), and are to be considered as falling within the scope of the following claims.
This latter arrangement, with each magnetic face bipolar, is even more effective than the solution with a single polarity for each face, as the magnetic force is double the preceding case.

Claims

A device (100) for holding a nail during its insertion into a surface (S) of a solid object, said device comprising a body (1) presenting at least one V-shaped seat (8, 80) the walls of which are defined by magnetic means (20, 21; 92, 93), said seat (8, 80) having a slot (9, 90) open at its ends (9A, 9B) and presenting a longitudinal axis (K) perpendicular to a plane of a base face (2) of said body (1), said magnetic means (20, 21) retaining the nail during its insertion, characterised in that the magnetic retention means present on the adjacent walls (16, 17) of the V-shaped seat (8) are mutually independent elements (20, 21; 92, 93) presenting opposing polarities, the positive polarity of a first magnetic element hence opposing the negative polarity of the second.
A device as claimed in claim 1, characterised in that the magnetic elements (20, 21; 92, 93) each present a single polarity.
A device as claimed in claim 1, characterised in that the magnetic elements (20, 21; 92, 93) each present the two polarities on the walls (16, 17) of the seats (8, 80) in which they are positioned.
A device as claimed in claim 3, characterised in that the polarities of a first magnetic element (20, 21; 92, 93) are of opposite sign to the polarities of the second magnetic element (20, 21; 92, 93).
A device as claimed in claim 1, characterised in that that end (9A) of the seat (8, 80) facing the surface (S) of the solid object into which the nail is to be inserted lies at a distance from said surface, said distance (d) being at least equal to the length of the usual conical point of a nail of average length.
A device as claimed in claim 1, characterised in that its body (1) presents the seat (8) for the nail at an end thereof.
A device as claimed in claim 1, characterised in that its body (1) presents seats (8, 80) for a corresponding nail at both its opposing ends (5, 6), said seats (8, 80) being of different length dimensions along their longitudinal axis (K) and having different angular apertures, the shorter seat having the smaller angular aperture.
A device as claimed in claim 1, characterised in that the base face (2) of its body (1) rests on the surface (S) of the object into which the nail is to be inserted.
A device as claimed in claim 1, characterised in that the base face (2) of its body (1) presents feet (110, 120, 130) by which it rests on the surface (S) of the solid object into which the nail is to be inserted.
A device as claimed in claim 1, characterised in that its body (1) presents an arm (190) jutting laterally and carrying at its end the seat (8, 80) for the nail.
A device as claimed in claim 1, characterised in that its body (1) presents a gripping element (4) rising from a face (3) opposite its base face (2).
A device as claimed in claim 1, characterised in that elastic retention means (300) are positioned at said seat (8) to retain the nail in said seat (8) during its hammering.
A device as claimed in claim 11, characterised in that the elastic retention means are a blade (300) rigid with that end (6) of the device body (1) presenting the seat (8) for the nail, said blade being profiled and presenting a protuberance (62) complementary to said seat, to cooperate with said nail in order to retain it in this latter.
A device as claimed in claim 13, characterised in that the protuberance (62) presents a flat surface (25) at its end.
A device as claimed in claim 13, characterised in that the blade (300) presents a first end portion (66) fixed to the device body (1) and a second end portion (74) separated from said body (1) and withdrawable therefrom to insert the nail into said seat (8) or to allow its relative extraction by withdrawing the body (1) from the nail after it has been inserted into the surface (S) of the solid object.