The automatic cutting machine is structured so that a sheet material spread on the cutting table can be carried in and cut to a desired form with a cutter knife adapted to be movable while moving up and down from above. When cutting, the cutter knife is freely moved back and forth and around in the state of its cutter blade being stabbed into the cutting table and, accordingly, the cutting table is formed by and paved with hard brush hairs, to allow such a free movement of the cutting knife. Further, the cutting table serves as a conveyer movable to carry out the sheet material after cut. For example, in the arrangement of a brush mount and a cut-support surface brush proposed by JP Laid-open (Unexamined) Patent Publication No. Hei 3-26496, each brush is adapted to be movable by the fit in longitudinally extending slots in the brush mount. In this arrangement, when the brush is mounted to and dismounted from the brush mount for replacement purpose, the each brush is moved and attached to and/or detached from an end of the brush mount.
This arrangement of the brush mount and the cut-support surface brush can allow the brush to move on the brush mount along the slots, but cannot allow the attachment/detachment of the brush from its own place. For example, when a brush have to be replaced, for example, for the reason that cut-support surface brush hairs located around a center of the cut-support surface formed by a number of cut-support brush hairs is damaged, the brush including the non-damaged brush hairs as well as the damaged brush hairs must be moved and removed from the brush mount for a while and then the block of brush hairs including the new brush hairs must be returned to the related brush mount. Thus, the arrangement above requires a time-consuming and troublesome work for the replacement. In order to save this trouble, the applicant of this application previously proposed, for example, in JP Laid-open (Unexamined) Patent Publication No. Hei 5-71067, an automatic cutting machine having a brush mounting structure for the cut-support surface that can allow the damaged brush to be removed from above the cut-support surface, for replacement with the new one.
However, in the structure that can allow removal of any desired brush by lifting it from above the cut-support surface, a clamping engagement between the brush and the brush mount is allowed by only a claming force of the order that can permit the brush to be lifted up by hand. Due to this, when a load more than an allowable load is applied to the brush or when a load is continuously applied to the brush from a particular direction, the claming force is weakened so that the brush may be disengaged from the brush mount. For instance, a comb-like member to scoop out the sheet material is fixed at an end of the cutting table in such a manner as to hide among the hard brush hairs so that when the sheet material, after cut, is carried to a carry-out portion of the cut-support surface by the cut-support surface serving as the conveyer, the sheet material can be released from the cut-support surface by the comb-like member. With this arrangement, when the hard brush hairs are intertwisted and thereby arranged nonuniformly during the uninterrupted operation, a load more than the allowable load is applied to the brush from a front side with respect to a traveling direction of the conveyer or a continuous load is repeatedly applied to the brush in the long run. As a result of this, the claming force for clamping engagement between the brush and the brush mount is weakened earlier, producing the problem of increasing the likelihood that the brush may be disengaged from the brush mount.