Abstract: A pipe layer attachment for an excavator includes a winch configured to wind and unwind a cable having a hook attached thereto. The pipe layer attachment also includes a pipe layer boom configured to mount onto a boom of the excavator as a cantilever with the pipe layer boom extending beyond an end of the boom. The pipe layer boom is configured to be connected to an arm attachment pin connection of the boom and an arm cylinder pin connection of the boom.

Abstract: The invention concerns an arrangement for machining a valve seat (1a) in a valve housing (1). The housing has a circular opening (1d) which is concentric with the seat (1a) and about which is a flat annular surface (1e). The arrangement comprises a support (2) arranged such that it is held by the valve housing (1) and such that, in an axial direction perpendicular to the plane of the annular surface (1e), it holds a tool pillar (3). At its distal end the tool pillar (3) has a machining tool (4). The support (2) comprises firstly a main part with three wings uniformly distributed about the tool pillar (3). Each wing comprises a first wing part (2b) which is operatively connected to the first wing part so that these wing parts (2a, 2b) can slide relative to each other along the sliding surface. Members (2b2, 2b3, 2b4, 2b5) are provided for detachably securing the wing parts (2a, 2b) relative to each other and the support (2) relative to the valve housing (1).

Abstract: The present invention relates to an arrangement for grinding planar annular surfaces (6; 8), especially the sealing surfaces of a valve. The arrangement comprises a hub (15) disposed rotationally fixed and bearing a planetary disc (16) mounted rotatably on the hub (15) and bearing in turn around its periphery a plurality of grinding heads (17) each having a grinding disc (19) mounted rotatably in its respective grinding head (17). The planetary disc (16) is effectively connected to a drive shaft (4) by means of which it can be caused to rotate relative to the hub (15). Between the hub (15) and the grinding discs (19) there are effective connections (31, 32, 33, 34, 35, 36) adapted to cause the grinding discs (19) to rotate relative to their respective ginding heads (17) when the planetary disc (16) is rotated relative to the hub (15). It is characteristic of the invention that the drive shaft (4) is mounted in the center of the hub ( 15) in such a way that it can be pivoted through approximately 180.degree.