Abstract:
The invention relates to a multipurpose magnetized device for immobilising an object on a magnetic or ferro-magnetic surface or grasping an object. Said device includes a lever arm ( 2 ) and a magnetized surface ( 1 ) separated by a line of rotation ( 3 ). Said magnetized surface makes it possible to fix the device either to a worktop or another object, or to another magnetized semi-clamp. The device is particularly intended to fix objects to a worktop, in particular to a large worktop, or to a “magnetic” board.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to a multipurpose magnetized device, which will be called bellow magnetized semi-clamp, for immobilising an object on a magnetic surface or forming pliers making it possible to grasp an object or to exert a gripping force.  
         [0002]     A magnetic surface means the surface of an object which is subjected to a magnetic force under the influence of a dipolar magnetic source.  
         [0003]     Specifically, objects made up of ferromagnetic materials are among these objects which surface will be described as a magnetic surface, i.e. surface to which a magnet can stick by magnetic attraction.  
         [0004]     By magnetized device, one means a device including magnetic materials distributed or traversed by an electric current so as to create a magnetic field characterized by the appearance of north and south poles on at least one of the device surfaces. Thereafter, we call such device surface magnetized surface.  
         [0005]     The fastening of parts, sheets, fabrics or objects onto a worktop is traditionally achieved by fastening means inserted into the worktop. To have them, the worktop must be equipped (opening, projection, grooves that make it possible to fasten the fastening means onto the worktop).  
         [0006]     So fastening points are inserted into the worktop. Their position is definitely fixed unless complex devices made up of rails or sliding systems are installed so that it be possible to fasten a part anywhere on the worktop. These devices are then complex to implement, specially on large worktops.  
         [0007]     Use of fastening device made up of permanent magnets is not very widespread. It is limited to the use of low-intensity magnets (for example on “magnetic” boards) because of difficulty in taking off or correctly positioning a magnet of more important intensity on a worktop. Moreover, powerful permanent magnets lead to constraints when transported because of the permanence of magnetic field and its associated attraction force.  
         [0008]     The majority of existing devices fasten the object between a magnetized surface and a magnetic surface, for example in U.S. Pat. No. 6,302,363 B1 issued Oct. 16, 2001, U.S Pat. No. 2,693,370 A issued Nov. 2, 1954 or U.S. Pat. No. 4,971,278 A issued Nov. 20, 1990 or in the E.P. Pat No 1,502,767 A issued Feb. 2, 2005. Their drawback is that they ensure only the fastening of thin objects.  
       BRIEF SUMMARY OF THE INVENTION  
       [0009]     The present invention makes it possible to remedy these drawbacks.  
         [0010]     It makes it possible to be freed from difficulties associated with permanent magnets by constituting a complex easy to take off, to handle and to transport while authorizing important attraction forces.  
         [0011]     Moreover it constitutes a general-purpose device that can be converted into gripping pliers by putting face to face two elements, whether identical or not, both jaws of the pliers being interdependent without the help of any machine part, their alignment and their swivel being achieved thanks to an ingenious distribution of magnetic masses. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The appended drawings disclose the invention:  
         [0013]     Magnetized surface ( 1 )  
         [0014]     Lever arm ( 2 )  
         [0015]     Line of rotation ( 3 )  
         [0016]     Worktop ( 4 )  
         [0017]     Part ( 5 )  
         [0018]     Separating line of poles ( 6 )  
         [0019]     Aperture angle ( 7 )  
         [0020]     Claw-shaped part ( 8 )  
         [0021]     Angle formed by the lever arm and the magnetized surface whose apex is the line of rotation ( 9 )  
         [0022]     Groove ( 10 )  
         [0023]     Northern magnetic pole ( 11 )  
         [0024]     Southern magnetic pole ( 12 )  
         [0025]     Axle ( 13 )  
         [0026]     Maximum leverage ( 14 ) 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]     In its simplest mode of realization, shown in profile FIG. ( 1 ) and viewed from the underside FIG. ( 3 ), the device, subject of the invention and called magnetized semi-clamp, includes a magnetized surface ( 1 ), a lever arm ( 2 ) and a line of rotation ( 3 ) located between the magnetized surface and the lever arm.  
         [0028]     The magnetized surface of the magnetized semi-clamp is intended to be put in total or partial contact with a partially or completely magnetic worktop or object ( 4 ).  
         [0029]     The force of magnetic attraction creates a tightening torque around the line of rotation ( 3 ).  
         [0030]     The worktop is a surface which is not necessarily plane.  
         [0031]     The magnetized semi-clamp ensures the immobilization of the part ( 5 ) on either the worktop or the object ( 4 ), the part being wedged between the magnetized semi-clamp and the worktop or the object ( FIG. 4 ) under the influence of the magnetic force.  
         [0032]     The lever arm ( 2 ) ensures the easy separation of the clamp from the surface by swivelling around the line of rotation ( 3 ) of the clamp ( FIG. 2 ).  
         [0033]     The line of rotation ( 3 ) is, at any time, the axis of rotation of the device that passes through the one or more contact points between the magnetized surface and the worktop.  
         [0034]     The magnetized surface ( 1 ) includes a line that will be called the separating line of poles ( 6 ), this line being approximately the perpendicular bisector of the segment bounded by both the center of gravity of south poles and the center of gravity of north poles of magnetization of the surface. One finds a &lt;&lt; force &gt;&gt; of south pole on a side of the separating line of poles as great as the &lt;&lt; force &gt;&gt; of north pole on the other side of the line, the centers of gravity of both north poles and south poles being of the same mass on the magnetized surface ( 1 ).  
         [0035]     The shape of the lever arm ( 2 ) is selected so as to make it possible the user to exert either a roughly orthogonal force on the magnetized surface or a torque towards the line of rotation ( 3 ) of the magnetized semi-clamp.  
         [0036]     This arrangement prevents the slip of the magnetized semi-clamp on the worktop when an operator exerts an action on the lever arm. The shape can be adapted according to the friction coefficient between the worktop and the magnetized semi-clamp.  
         [0037]     In accordance with the objective of the present invention, the angle formed by the lever arm and the magnetized surface whose apex is the line of rotation ( 9 ) can have a value higher than 145°. This particular configuration is shown on  FIG. 2 .  
         [0038]     In accordance with the objective of the present invention ( FIG. 3 ), the separating line of poles ( 6 ) can be perpendicular or almost perpendicular to the line of rotation ( 3 ), which can itself be aligned or almost aligned with the maximum leverage ( 14 ), i.e. the lever arm segment which is orthogonal to the swivel axis and passes through the point of the magnetized semi-clamp which is at the longest distance from the swivel axis.  
         [0039]     This configuration makes it possible to have a continuous attraction force between the magnetized surface and the worktop as the aperture angle ( 7 ) between the magnetized semi-clamp and the worktop increases. Moreover it avoids that the magnetized semi-clamp slips on the worktop at the time of its opening, the line of rotation remaining in contact with the worktop.  
         [0040]     In accordance with the objective of the present invention, the line of rotation ( 3 ) can be a straight line. This configuration makes it possible to position the magnetized semi-clamp on the worktop, then to open it in order to slip an object between the magnetized semi-clamp and the worktop that comes to be propped up against the line of rotation ( 3 ).  
         [0000]     In accordance with the objective of the present invention:  
         [0000]    
       
         
           
              the line of rotation ( 3 ) can be realized by one edge of the magnetized semi-clamp, in particular if this line of rotation is used to position objects wedged under the magnetized semi-clamp  
              the line of rotation can have a curved section, this curved section can be set with devices, casters, balls or other ones on its external edge, thus facilitating the mowing of the semi-clamp once this one is opened on the worktop  
              the line of rotation can have a groove ( 10 ) making it possible to wedge the magnetized semi-clamp either on the worktop or on the object or to fix two magnetized semi-clamps to each other by inserting an axle ( 13 ) in the groove (FIGS.  20  to  25 , profile views)  
           
         
       
     
         [0044]     In accordance with the objective of the present invention ( FIGS. 14, 16 ,  18  et  19 , magnetized surface of the device viewed from the underside), the separating line of poles ( 6 ) can approximately be an axis of symmetry of the magnetized surface ( 1 ) geometry, as magnetic fields crossing two surface elements symmetrical in reference to the separating line of poles are opposite with consequently an anti symmetric distribution of north poles and south poles on both sides of the separating line of poles.  
         [0045]     By then this arrangement makes it also possible to form magnetized pliers by bringing together two magnetized semi-clamps identical or not ( FIG. 9 ). In this configuration, the symmetry of the device ensures an automatic centering of both semi-clamp one with regard to the other, separating lines of both semi-clamp being approximately merged when the pliers are closed. The line of rotation is then the axis of opening of the pliers.  
         [0046]     Correspondences between south poles and north poles when two semi-clamps are brought together according to this particular mode of realization are shown for two particular configurations on  FIGS. 15 and 17  viewed from the underside.  FIGS. 18 and 19  show two other examples of possible distributions of poles also viewed from the underside.  
         [0047]     This arrangement makes the transport of the magnetized semi-clamps easier, the semi-clamps being transported in pairs, pressed one against the other.  
         [0048]     In accordance with the objective of the present invention(figures  5 ,  6 ,  7  et  8 ), the magnetized semi-clamp can have an elastic claw-shaped part ( 8 ) making it possible to fasten thick parts while keeping a high gripping force. The elasticity of the elastic claw-shaped part ( 8 ) is suited to the attraction force produced by the magnetized surface ( 1 ), to the lever ( 2 ) and to the gamut of thicknesses for which the device works.  
         [0049]     The device according to the invention is particularly intended to the fastening of objects onto either a worktop, in particular large worktop, or a “magnetic” board.