GB778091A - Chair lift - Google Patents

Abstract

778,091. Stairway lifts; preventing slack in electric cables. SHEPARD ELEVATOR CO. June 6, 1955 [April 26, 1955], No. 16218/55. Classes 78 (2) and 78 (3). In a stairway lift, a rail assembly 32 adapted to be secured to a stairway is provided with a rail 43 co-operating with driven rubber rollers 46, 56 on a lifting carriage, and a rail 44 which co-operates with rollers 101 on an arm 95 to pivot the seat 35 relative to the carriage about the axis of the drive-shaft 54 of roller 46 so maintaining the seat horizontal regardless of the slope of the rail assembly. Further stabilizing rollers 67, 68 and (other rollers not shown) are provided on the carriage to guide it along the rail assembly. Rollers 46, 56 are belt-driven through worm reduction gear by an electric motor 33 which is controlled by an electric circuit (Fig. 26, not shown) which includes upper and lower call buttons, control buttons on the seat arm 37 and cut-out switches operated by a passenger's weight on the foot-rest 91, by the drive belt running slack and by a motor overload. The lift is provided with automatic means for braking the reduction gear when the motor is de-energized. Stack prevention.-Current is fed to the motor and control switches by a cable 40 which is wound on a drum 41 on the shaft 54. A balltype, one-way clutch (Figs. 13-16, not shown), is provided between the drum hub and shaft 54 so that when the carriage is being lowered the cable, which is anchored at its upper end, is paid out under slight tension, whilst when the carriage is being raised the cable is wound on to the drum. Catch gear.-A shaft 108 (Fig. 18) is rotatable by a knurled wheel 110 engaging rail 43, and carries a pair of spring-loaded weights 112 which, on attainment of excessive speed, overcome spring 124 and strike a bar 106. Movement of this bar rotates a further knurled wheel 111, eccentrically pivoted on shaft 108, and forces it into gripping engagement with rail 43.