to a barrel 58 of the skid cylinder 15 by pins 50 and 51 located on either side thereof fig1 illustrates the skid device horizontally guided in the back by a groove 53 provided in the pad 22 with the pad remaining free to move in all planes fig1 illustrates an alternate embodiment of the device of fig2 in this case the skid cylinder 15 is attached to the bar guide 11 by pins 70 located on either side of the cylinder barrel fig1 and 13 illustrate a device wherein guide bars 60 are not retained by a guide which requires a greater length for the bars and results in a significant oversize in the back this disadvantage is alleviated by the fact that the skid bars are the only members exposed to the rock falls from old workings as illustrated in fig1 an arm 62 rests against the guide bars 60 and a pad 61 in order to reinforce the bar assembly a rear cross bar 63 fig1 may be included the skid device may be adapted for use with single block pads the rear cross bar 63 fig1 no longer has to provide the displacements of one pad with respect to the other and it solely transmits the efforts furthermore the joints or connections 24 and 25 do not require as much operating free play as they would in the case of separate pads although the best mode contemplated by the inventor for carrying out the present invention as of the filing date hereof has been shown and described herein it will be apparent to those skilled in the.