Abstract:
A device for centering and gripping, particularly for automotive bodywork parts, comprises a body ( 1 ) with an actuating means ( 2 ) and has centering means ( 13 ) and gripping means ( 11, 12 ). The centering means ( 13 ) and the gripping means ( 12 ) comprise in combination a centering member ( 13 ) containing at least one retractable gripping member ( 11  or  12 ).

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a device for centering and gripping, particularly for automobile bodywork parts, of the type comprising a body with an actuating means and having centering and gripping means. 
     2. Description of the Related Art 
     In this technical field, there is commonly used as actuating means a hydraulic jack, a pneumatic jack, an electric jack or a remote actuating means that can transmit force by means of a cable or another suitable flexible connection means. 
     There are known means for positioning and centering, adapted to be inserted in an opening for positioning a metal sheet of automobile bodywork or a piece for automobile construction. 
     There is also known means for gripping and holding comprising a gripping or holding arm, whose blocked position is substantially perpendicular to the axis of pressure of the actuating means. 
     SUMMARY OF THE INVENTION 
     The invention has its object to improve the known technique, by providing a new device for simple and economical production ensuring simultaneously the centering and the gripping of a metal sheet or a piece for automobile bodywork. 
     The invention has for its object a device for centering and gripping, particularly for automobile bodywork parts, of the type comprising a body containing an actuating means adapted to actuate in combination at least one retractable gripping means and a centering member containing each retractable gripping member within said centering member, each gripping member having an end forming a hook extending radially outwardly and downwardly, characterized in that the device comprises mechanical means for return movement, connecting said actuating means to the centering and gripping members, so as to move the actuating means and the centering gripping members in a direction opposite to displacement of the centering member. 
     According to another characteristic of the invention: 
     the centering member has a conical upper engagement end, and an intermediate centering portion which is substantially cylindrical, 
     the pivoting of each gripping member is controlled by an axle secured to the centering member, 
     the axle secured to the centering member is movable relative to the body of the device, 
     the axle secured to the centering member is moved with a movement opposite that of the actuating means, 
     the device comprises self-blocking crampons, 
     the self-blocking crampons pivot about axles secured to the body of the device, 
     the self-blocking crampons coact with an intermediate floatingly mounted piece, 
     a movement of the axle is opposite to that of the actuating means, by means of a connecting rod pivotally mounted on a control square, 
     the control square is rotatably mounted on an axle secured to the body, and comprises an opening in which is positioned an axle indirectly connected to the actuating means. 
     The movement of the axle  10  is ensured, in a direction opposite to that of the actuating means  2 ,  3  by means of a connecting rod  9  mounted pivotably on a control square  8 . 
     The control square  8  is rotatably mounted about an axle  8   a  secured to the body  1 , and comprises an opening in which is positioned an axle  7   b  indirectly connected to the actuating means  2 ,  3 . 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood from the description which follows, given by way of non-limiting example, with reference to the accompanying drawings, in which: 
     FIG. 1 is a schematic cross-sectional view in a medial plane of a device according to the invention in the centering position. 
     FIG. 2 shows schematically in cross-sectional view in a medial plane the device of FIG. 1 in the position at the beginning of gripping. 
     FIG. 3 shows schematically a cross-sectional view in a medial plane of a device according to FIGS. 1 and 2 in a position ensuring simultaneously centering and gripping. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to FIGS. 1 to  3 , identical or functionally equivalent elements are given identical reference numerals. 
     In FIG. 1, a device according to the invention has a body  1  machined in its lower portion to provide a jack  2  with a piston  3  and a closure cover  4  fixed by screws  4   a  with interposition of a suitable sealing joint  4   b.    
     The piston  3  is connected by a screw  5  to an intermediate piece  6  having a rod  6   a,  an intermediate cylindrical portion  6   b,  and an upper portion  6   c  carrying an axle  6   d.  The piece  6  is mounted at least partially in a member  7  displaceable in translation and mounted floatingly because the bore  7   a  of the piece  7  has a diameter greater than the axle  6   d  of piece  6 . 
     The piece  7  has an axle  7   b  which is positioned in an opening of a swingable member  8  rotatably mounted about an axle  8   a  secured to the body  1 . The swinging piece  8  in the form of a square has a control opening  8   b  and an axle  8   c  on which is mounted pivotably a connecting rod  9 . The connecting rod  9  has a control axle  10  which slides in an opening  11   a  which is curved or shaped like a broken line, of a gripping member  11 . Preferably, the device comprises two gripping members  11  and  12  so as to ensure symmetrical gripping of a metal sheet or piece of bodywork. 
     The gripping members  11  and  12  are retractable in a centering member  13  having an upper cylindrical engagement end  13   a  and an intermediate portion  13   b  that is substantially cylindrical. 
     The gripping members  11 ,  12  contained in the centering members  13  are slidably mounted in a ring  14  mounted in an upper body  15  capped by a protective member  16  with the interposition of a scraping joint  21 . 
     In the position of FIG. 1, the device is in the lower position B, in which there can be inserted a metal sheet from above the centering member  13 . The grippers  11  and  12  are retracted within the centering member  13 , because the axle  10  is disposed in the lower position and inclined from the control path  11   a  of the member  11 , and  12   a  of the member  12 . The axle  7   b  and the member  7  are in the upper position, because the piston  3  of the jack and the piece  6  which is directly connected to it, are located in the upper position. In this position, the axle  6   d  bears on the upper edge of the bore  7   a  of the piece  7 . 
     In the position of FIG. 1, and the position of FIG. 2, compressed air is admitted into the upper chamber of the jack, so as to cause the movement of piston  3  downwardly. In the intermediate position of FIG. 2, the axle  6   d  and the piece  6  are moved downwardly until the position in which the axle  6   d  bears on the lower edge of the bore  7   a  and causes displacement of the piece  7  downwardly. The axle  7   b  causes swinging of the control square  8  by pulling on the latter in cooperation with the opening  8   b.  This swinging of the square  8  causes rising of the connecting rod  9 , of the axle  10 , and of the piece  13  to which the axle  10  is secured, as well as the outward movement of the members  11  and  12  because of the circulation of the axle  10  along the path  11   a.    
     When the movement of the piston  3  downwardly is complete, the control square  8  has almost totally swung downward and the axle  10  of the connecting rod  9  is almost at the end of the path  11   a,  giving rise to the complete moving out, at the same time as the descent, of the gripping members  11  and  12  each having an end forming a hook extending radially externally and downwardly. At the same time, the member  13  on which is mounted the axle  10  has moved from its highest position H, this highest position H being higher than the low position B by a height comprised between 2 and 30 mm. 
     The metal sheet or piece of bodywork is accordingly gripped between the hooks of the members  11  and  12  which apply it to the protective member  16  and it is centered by the cylindrical portion of the centering member  13  which has moved from a height corresponding to the distance comprised between the heights B and H. 
     According to a preferred modification of the invention, there are provided self-blocking crampons  17 ,  18  articulated for rotation about axles  17   a ,  18   a  secured to the body  1 . In the position of FIG. 1, the crampons  17 ,  18  are open and do not prevent movement of the pieces  6  and  7 . 
     In the position of FIG. 2, the crampons  17 ,  18  begin to again grip by engaging in the ramps  7   c ,  7   d  provided in the piece  7 , the movement of the crampons  17 ,  18  being controlled by chamfers  6   e ,  6   f  bearing on the lower edges of the crampons  17 ,  18 . 
     In the position of FIG. 3, the crampons  17 ,  18  are locked in position along the ramps  7   c ,  7   d  (FIG. 2) because of the immobilization of the crampons maintained by the surfaces, for example flat, of their lower ends bearing on the cylindrical periphery  6   g  of the cylindrical portion  6   b  of the piece  6 : in this position, even in case of a lack of compressed air or interruption of the control circuit, the crampons  17 ,  18 , locked in the ramps  7   c ,  7   d , prevent any unlocking of the device according to the invention. 
     In particular, the control square  8  could be replaced by another control member mounted for rotation on an axle spaced from the longitudinal axis of translation of the movable members of the device, namely the axis of symmetry of the piece  6 .