Abstract: A manual appliance for cutting pipes made of plastic, such as polyethylene, comprising a cutting blade mounted on a blade-holder moving under the action of a control screw between the two parallel branches of a guide saddle closed by means of a completely opening lower saddle.

Abstract: The invention relates to an on-site pipe-cutter assembly which is intended for manual sectioning of rigid, large-diameter pipes located in narrow trenches. The pipe-cutter assembly includes two yokes (1,2) which are connected at their associated ends by tie bars (3) and nuts (4), the yokes including cutter wheels (5) and ratchet sectors (9) arranged at the periphery of the yokes (1,2), the ratchet sectors being concentric with the cutter wheels (5) and a lever (12) having with a forked end which is equipped with two pawls, the pawls making it possible to obtain changes in the angular position of the lever by 10.degree. to 15.degree. or by a multiple of this angle.

Abstract: The present patent relates to chain pipe-cutters equipped to cut all kind of material. The chain pipe-cutters include: a tensioner which is a deformable system formed by a cylindrical rod fast with a support, a slider slidably mounted on said rod, said support bearing four articulated rockers connected to the slider in pairs by two links and having their lower ends shaped as hooks to permit attachment of the chain thereon; said cylindrical rod cooperating with a handle through the agency of a screw-thread and said handle being formed by two superimposed cylindrical elements and having four superimposed lobes arranged cruciform-fashion.

Abstract: Apparatus for rotating a cylindrical workpiece to be machined, having one or two automatic clamping devices on a rotatable hollow driven shaft into which the workpiece is inserted. Each clamping device has three chuck jaws mounted to swing into clamping engagement with the workpiece. Two pivots are provided for each jaw which swings about one or the other of them depending on the direction of rotation: the provision of two pivots gives a smaller and less cumbersome apparatus. To make the pivots swing into clamping engagement, a floating drag plate is freely rotatable on the shaft adjacent the clamping device. It is braked, to restrain rotation with the clamping device but it is positively linked to each jaw by a gudgeon pin, so that on rotation of the clamping device the braking restraint on the floating drag plate is transmitted to the jaws and urges them into clamping engagement with the workpiece.