GB1250698A - - Google Patents

Abstract

1,250,698. Masted lift trucks. CLARK EQUIPMENT CO. 19 Dec., 1969 [21 Jan., 1969], No. 62138/69. Heading B8H. In a masted lift truck in which forward tilting of the mast is normally limited by the opening of a mechanically-actuated limit switch in the control circuit, a manuallyoperable override switch is provided to permit further forward tilting of the mast beyond the normal limiting position. As shown, when the limit switch 60 is closed, the solenoid valve 54 opens whereby, when a selector valve 34 directs fluid through a line 48 to the tilt rams 30, 30<SP>1</SP>, the return flow from the rams passes through the valve 54. When the switch 60 is opened, the valve 54 closes and cuts off the return flow from the rams 30, 30<SP>1</SP>. If a manually-operated switch 62 is closed, thereby by-passing the switch 60, the valve 54 re-opens to allow further extension of the rams 30, 30<SP>1</SP>. In either position of the valve 54, the mast may be tilted rearwardly by operation of the selector valve 34 to pass pressure fluid through a line 50 and either a passage A or a one-way valve B in the valve 54 to the upper ends of the ram cylinders. The limit switch 60 is mounted on a fixed part of the truck and is actuated by a stepped slide which is movable in a guide on the truck and which is connected by a pivoted link to the mast, Figs. 3-5 (not shown). In a modification, Figs. 6-8 (not shown), the pivoted link is replaced by a telescopic link containing the limit switch.