Patent GB-879841-A (GB)
Title: Machine for transmitting power by flexible shaft
IPC: F16C1/02
Filed: 1959-11-20
Abstract: 879,841. Flexible shafts; friction clutches; shaft couplings. MORRIS (AUST.) PTY. Ltd., B. O. Nov. 20, 1959 [Dec. 18, 1958], No. 39459/59. Class 80 (2). [Also in Group XXVIII] Mechanism for transmitting power from an electric motor 20, Fig. 1, to a flexible shaft 37 which may drive a cutter or scraper head used for removing deposits of scale &c. from the inner walls of pipes, comprises a tubular shaft 17, Fig. 7, driven by the motor and slidably connected by a key 25 or the like to an inner shaft 23, a clutch 26 transmitting drive from the inner shaft to the flexible shaft. The clutch 26 is controlled by a hand lever 56 which slides the clutch body as a whole along its axis to pay out the flexible shaft, as when the scraper head or cutter advances down the pipe, the end of a sliding motion by the hand lever serving to disengage the clutch, so that it may be slidden axially of the flexible shaft 37 back to its initial position and then re-engaged. The clutch 26 comprises a driving hub 39 fast with the inner shaft 23 and secured to an outer clutch member 27 on which are pivoted several levers 30. The inner ends 31 of the clutch levers 30 engage a collet 32 surrounding the flexible shaft 37 and having frusto-conical surfaces 33, 34 at its end separated by axial slots 35. A thrust cone 38 splined to the driving clutch hub 39 coacts with the longer ends of the levers 30, and turns them either to a position in which they wedge the collet 32 into frictional engagement with an internally frusto-conically surfaced bush 36 fast with the driving hub and on to the flexible shaft 37, or alternatively allows them to remain free when the collet is able to slide along the flexible shaft. The thrust cone 38 is controlled by a non-rotatable yoke 45 carrying arms 40, Fig. 6, which coact alternatively with adjustably positioned stops 57, 58 on the frame 10 Fig. 1, of a two-wheeled trolley mounting the apparatus. The arms 40 are connected through links 47, 48 to a cross-bar 49 in turn fast with a plate 51 coacting through a bearing with the rear end of the clutch 26. The crossbar 49 slides in guides 50 in the sides 10 of the trolley. Links 54, 55 are pivoted to the trolley frame, and the hand lever 56 is fast with the plate 51. Movement of the handle 56, e.g. rightwards of Figs. 3, 7, slides the whole clutch 26 and the flexible shaft axially with respect to the trolley. When the arms 40 contact one or other of the adjustable stops 57, 58, the arms are turned and the impact disengages the thrust cone 38 from the ends of the levers 30. The clutch then disengages and the hand lever 56, together with the clutch body 26, can be slidden back leftwards, leaving the flexible shaft 37 in the position to which it has been moved. When the arms 40 strike one or other of two further adjustable stops 59, 60 upon the frame of the trolley, the thrust cone 38 is jerked between the ends of the clutch lever 30 and the clutch 26 re-engages. Drive then recommences. In the form shown, a clutch 61 of similar construction is also mounted on the trolley, this clutch operating in the opposite direction of axial sliding motion to the clutch 26, so that drive to the flexible shaft 37 is constantly maintained. Instead of axial sliding of the clutches 26, 61 being produced by manual operation of the hand lever 56, automatic means (not further described) may be provided for operation by the motor 20.