support device 1 represented in fig1 consists of a box , for example made of a sheet of heat - resistant steel . a wall 2 appears on the top and a closed vertical wall 3 appears on the sides . the box is open at the bottom . bottom face 4 of wall 3 is located in a plane . wall 3 has a shape that corresponds to the size and periphery of the sheet to be lifted , so that the outside shape of bottom face 4 and the outside shape of the lifted sheet are in congruence . if the thickness of wall 3 reaches , for example , 3 mm when the glass sheet is lifted , only a small portion of its surface , in this case a 3 mm strip on the edges of the sheet , is in contact with the support device . as is customary for suction devices of this art , a fan 5 is fastened directly to the support device . fan 5 sucks air into the cavity of the box through opening 6 and pipe 7 . fan 5 can be adjusted finely and accurately and the suction effect is dependent on the weight of the glass sheet to be lifted , which means that the regulating is performed as a function of the size and thickness of the sheet so that the pressure difference obtained holds the sheet securely against bottom face 4 without producing bothersome crosswise bending . depending on the situation , a regulating cycle is provided for regulating fan 5 as a function of the partial vacuum prevailing in the box closed by the glass sheet . support device 1 is upwardly mobile , however , to simplify the diagram the corresponding equipment is not shown in fig1 and 2 . it is the same for the other equipment necessary for the good operation of the device and that is well - known to a man of the art . included in these is a device for accurate positioning of the glass sheet moving on the conveyor belt and the devices for controlling the raising - lowering movements of device 1 and those connected to fan 5 . support device 1 shown in fig1 is suited only for glass sheets of a given shape ; at each change of shape it is also necessary to change the support device . on the other hand , support device 10 shown in fig2 can be adapted in a simple manner to various shapes of sheets . the box consists in this case of a rectangular top plate 12 and of lateral walls 13 , 14 also rectangular which delimit a cavity whose section in a horizontal plane is larger than the surface of the sheet to be grasped . underneath , the box is closed by an interchangeable flat plate 15 . in this plate 15 is an opening 16 whose shape corresponds to the shape of sheet 17 . in this manner , the contact between plate 15 and glass sheet 17 occurs only along a narrow strip 18 whose width b has an order of magnitude of 2 to 5 mm . the fastening of interchangeable bottom 15 to the box is obtained according to suitable means by taking care to assure appropriate airtightness between plate 15 and walls 13 , 14 . to adapt the support device to glass sheets of another size , it is enough to replace plate 15 with another plate whose opening 15 corresponds to the new size of the glass sheets . the support device described with reference to fig1 and 2 is more particularly useful in all cases where a glass sheet heated to the bending temperature must be lifted from a conveying device , then deposited on another support particularly on an annular or solid bending form on which the glass sheet is bent under the effect of its weight . in these cases , it is substituted for known suction plates . the support device according to the invention can also , because of its particular design , be used for other bending processes according to which the shaping of the glass sheet 17 results from pneumatic pressing against a bending form placed above the glass sheet . its use with such a bending process is described below with reference to fig3 which represents a bending station in detail . the bending station comprises a horizontal conveyor made of conveying rollers 20 by means of which glass sheet 21 is conveyed through a furnace , not shown , then from this furnace to the bending station to be placed under a solid bending form 22 . bending form 22 is fastened to a pipe 23 itself attached to a frame 24 . frame 24 is suspended by chains or cables 25 which are operated by pulleys 26 placed on the outside of the housing surrounding the bending station . pulleys 26are controlled by motors 28 thanks to which bending form 22 can be raised or lowered . bending form 22 is placed in a vertical conduit 30 in which a current of air heated to about 600 ° c . circulates upward with a given pressure and volume . lateral wall 31 of conduit 30 exhibits at the top of the bending chamber itself , an opening 32 making possible the penetration of glass sheets 21 . wall 33 exhibits an opening 34 that is used for the removal of the bent glass sheet . the bending of glass sheets is obtained due to the hot gas current directed upward which presses glass sheets 21 against the face of bending form 22 directed downward . to convey the bent glass sheets outside of the bending station , a carriage 39 mounted on wheels 38 is provided on which a support ring 40 is placed whose shape and size correspond to the periphery of the glass sheet . carriage 39 rolls on two rails 42 which extend to the inside of the bending station . bending form 22 is surrounded by a box 44 which can be moved upward or downward independently of bending form 22 . for this purpose , box 44 is provided on its upper face with a frame 45 which is attached to four chains or cables 46 . chains or cables 46 pass through the upper wall of the housing surrounding the bending station and are operated from the exterior of the bending chamber by pulleys 48 . transmitted by belt 49 , the rotation of pulleys 48 is controlled by motor 50 which , in this manner , lifts or lowers box 44 . against pipe 23 that carries bending form 22 , the upper wall of box 44 is blocked by a seal 52 allowing relative movements between box 44 and bending form 22 . box 44 is provided with a fan 54 and exhibits on its lower face an opening which corresponds to the shape of glass sheet 21 and is slightly smaller than it so that the glass sheet is grasped and held along its outside edge by the surface of edge 55 limiting the opening of box 44 . the glass sheet heated to the bending temperature penetrates into the bending station through opening 32 and is exactly positioned by a mechanism not shown . during this time , box 44 is just above the conveying plane , so that the annular surface of edge 55 is above the upper surface of glass sheet 21 . bending form 22 that is on the inside of the box also assumes such a position that the lowest part of the bending surface is located a few centimeters above glass sheet 21 . as soon as glass sheet 21 is correctly positioned , box 44 is lowered just above sheet 21 while fan 54 is actuated . when the surface of edge 55 of box 44 comes in contact with sheet 21 , the latter is sucked and held by the partial vacuum in box 44 . box 44 and bending form 22 are then raised simultaneously , raising the glass sheet with them , the relative positions of these various elements remaining unchanged . carriage 39 and support ring 40 can then be placed under bending form 22 . when bending form 22 has reached its highest position , box 4 still continues to rise somewhat . at this moment , the hot gas current is established . while box 44 continues its rise relative to bending form 22 , glass sheet 21 is pressed against the bending surface of form 22 and is detached from the surface of edge 55 of box 44 . the weight of sheet 21 is then totally offset by the hot gas current which , in addition , exerts a uniform pressure and bends glass sheet 21 in the shape corresponding to bending form 22 . to assist the bending process and particularly the bending on the edges of the glass sheet , fan 54 can be kept operating . optionally , the suction effect of fan 54 can even be boosted at this time . during or just after this bending process , carriage 39 carrying ring 40 is brought under bending form 22 which is then lowered just above ring 40 . the hot gas current is eliminated or simple reduced and glass sheet 21 falls under the effect of its weight onto ring 40 . it is then conducted to the next processing station and the device is ready for a new bending cycle . obviously , numerous modifications and variations of the present invention are possible in light of the above teachings . it is therefore to be understood that within the scope of the appended claims , the invention may be practiced otherwise than as specifically described herein .