GB314135A - Improvements in hoisting apparatus - Google Patents

Abstract

314,135. Express Lift Co., Ltd., and Huggett, W. J. March 28, 1928. Jib cranes; overhead travellers and transports.-Apparatus particularly suitable for hoisting loads through the door of a building, comprises two or more arms 15, 16 pivoted to swing on vertical axes 14a, 11, and means such as a beam 21 pivoted to the outer ends of the arms and serving as a support for a hoisting device. As shown in elevation in Fig. 1 and in plan in Fig. 3, the beam 21 forms an overhead runway for a trolly 23. The hoisting rope 32 is anchored at one end of the beam at 47 and passes over sheaves 45, 42 on the trolly, the load block 43, a sheave 41 at the other end of the beam, a sheave 40 coaxial with a pivot of the beam, a sheave 37 on the arm 16, and a sheave 35 on the frame, to a winding drum 6. The rope bears against a sheave 33 which is arranged to move if the rope breaks and to operate a switch to stop the motor. The trolly 23 is moved along the beam by an endless rope 24 passing round a sheave 25 and a drum 26 operated by a motor 27 on the beam. Overwinding of the load and overrunning of the trolly are prevented by limit switches 48, 28. The arms 15, 16 are swung by a hand-wheel 30 and reversible worm gear. The arm 15 is only slightly shorter than the arm 16, so that the beam remains substantially parallel with its original direction. The pivot 14a of the arm 15 is carried by an arm 14 on the pillar 12 which may be turned by hand gear, not shown, so that the arm 15 may be swung independently of the arm 16 to slue the beam. Electric motors may be used for swinging the arms, and all the control panels may be on the fixed frame at 9. In a modification, Fig. 5, a beam 50 is carried by links 51, 52 supported by swinging arms 53, 54 and 55, 56, the extreme positions of the device being as shown in broken lines.