fit between panel 72 and the wall face 1 if members 54 56 58 68 and 70 were mounted rigidly and flush on the frame 50 no such preloading would take place so that excess force would be applied to the middle of the edge of the panel compared with the outer end if leaking at the middle were to be avoided fig1 and 3 show the use of an upper edge of the frame 50 as support brackets 73 to receive an elongated member 75 which extends beyond one frame 50 to engage the next frame 50 to maintain alignment of all the frames 50 along a wall the device operates as follows form 72 is positioned over a wall 1 in the manner shown in fig1 a hydraulic pump not shown is activated to force fluid into cylinder 36 causing it to expand as it does so fingers 40 44 and 46 are pivoted round their respective pins and spread apart fingers 44 and 46 push directly on beam 18 while eased by rollers 20 and 22 the beam slides outwardly to bring frame 50 and the carried panel 72 into contact with the wall face see fig3 simultaneously an identical operation is being performed within the other arm 6 of the form bowed inner bracing members 54 56 58 68 and 70 forced inwardly and as the clamping force is increased straightened thus preloading the lower edge of the panel and ensuring a tight seal member 56 imposes a similar loading on members 68 and 70 as does 54 on 58 concrete is then poured between the two panels 72 and left to set when the concrete is set the hydraulic pressure is relieved and the form removed it should be noted that.