GB847727A - Motor-driven constant-force support hangers - Google Patents

Abstract

847,727. Automatic tension control systems. GRINNELL CORPORATION. June 6, 1958 [June 12, 1957], No. 18102/58. Class 38 (4). A constant force support hanger comprises a supported member 43 to which a load, e.g. a pipe line 10, is applied, anchor means 13 for supporting the member, means for adjusting the effective length of the hanger between the load and anchor means comprising means for converting rotary motion to straight line motion, means for actuating the length-adjusting means by providing the former with the said rotary motion, means responsive to changes in force applied to the member 43 by the load for actuating the actuating means to adjust the effective length of the hanger between the load and the anchor means to compensate for the said changes in force, and means associated with and forming part of the hanger for neutralizing and retaining within the hanger rotary force in excess of that which is converted into straight line motion whereby substantially no rotary force is transmitted externally of the hanger. As shown in Fig. 1, the hanger comprises a hollow, cylindrical frame 12 carrying on an intermediate wall 14 thereof an electric motor 16 the drive shaft 18 of which is horizontal and carries a worm-gear 20 meshing with a wormwheel 22 secured to a vertically disposed screw member 26 receiving a nut member 36 provided with depending arms 38. Secured to the latter is a rod 42 connected to a rod 43 through a motor switch and switch control mechanism 45, the mechanism allowing the rod 43 to move vertically with respect to the rod 42 with vertical movement of the pipe-line. Extending radially from the member 26 is an arm 46 carrying a roller 48 lying in a slot 50 in the frame. Movement of the pipe-line upwardly or downwardly changes the force exerted by the pipe-line on the hanger and results in relative movement of the rods 42, 43 and the mechanism 45 is actuated to supply electrical power to the motor 16 to drive the latter in one direction when the force is decreased and in the opposite direction when the force is increased. Rotation of the worm-wheel 22 rotates the member 26 and the non-rotatable nut 36 moves up or down to compensate for decrease or increase in force exerted by the pipe-line. Rotation of the member 36 is prevented by the roller 48 engaging the sides of slot 50. Alternatively, the arm 46 engages a rod forming part of the frame, or a rod extends into an aperture in the nut so that the nut is free to move vertically with relation to the rod. In modifications (a), the screw member is threadedly received in the worm-wheel and is movable vertically; (b) two screw members 122, 124, Fig. 7, journalled in the frame 106 and geared to rotate in opposite directions, are used to actuate a single nut member 139; and (c) two screw members movable vertically with respect to the frame are connected by a cross-piece adapted to carry the pipe-line. Specification 534,940 is referred to.