摘要:
A hydraulically operated clamshell bucket including left and right bucket halves pivotally supported by a bucket carrier. The bucket halves are opened and closed by the operation of a hydraulic cylinder in cooperation with a compensation link. The clamshell bucket provides an improved structural arrangement for transmitting the force from the hydraulic cylinder to the cutting edges of the bucket halves in that for a given size and rated bucket, the weight of the bucket may be reduced along with the complexity and manufacturing cost of the bucket.
摘要:
Front and rear pairs of crawler assemblies are provided for supporting concentric ring segments disposed forwardly under the boom and rearwardly under the counterweight so the crane can travel under load and swing through at least a partial horizontal arc. One and preferably both crawler assemblies are selectively and reversely powered to facilitate forward and reverse as well as turning movement during travel under loaded and unloaded conditions. The inner ring segment is at least partially surrounded by a rotatable cage structure which provides a connection point for a frame element extending to the forwardly disposed crawler assembly to permit independent steering of the rear crawler assembly.
摘要:
A turntable bearing device having a quick release mounting including inner and outer ball bearing races with the inner race fixed to the lower works and the outer race is detachably connected to the upper works of a load handling device. Gear teeth are provided along the inner circumference of the inner race to engage a pinion gear of the upper works. The quick release feature includes an arcuate beam which is slidably carried on support rails and engages the outer bearing race on one side while a latching means is provided to engage the outer bearing race on its opposite side. The arcuate beam and the latching means prevent rocking or tipping motion of the upper works during machine operation as well as providing the quick release means.
摘要:
A traveling attachment including two pairs of crawler assemblies and frame elements are provided for interconnection to the ring of a ring supported crane so the crane can travel under load. The crawler assemblies may be pivotally mounted and reversely and independently powered to facilitate turning.
摘要:
A hoist drum drive control is provided with both variable displacement and fixed displacement motors geared to the drum and connected in parallel to a variable displacement pump. During high speed hoisting the variable displacement motor is shifted to zero displacement until the back pressure reaches a certain level at which time the displacement is automatically increased until a balanced condition is achieved. When lowering heavy loads a feedback to the variable pump decreases its displacement to prevent over speeding the engine.
摘要:
A self-erecting mast and boom for a lift crane including self-storing mast cylinders for erecting the mast and rotating a pivoted boom carrier into position to receive the boom which may then be raised by the boom hoist mechanism of the crane. A back hitch assembly including hydraulic cylinders is employed to initially raise the mast and the gantry members which may be lowered into horizontal position to reduce the crane profile for self-propelled transport between job sites.
摘要:
The back hitch assembly for a lift or tower crane includes a tension sensing device which regulates the pressure delivered to the boom stop or hold back cylinders such that as the boom hoist line and back hitch become slack when the load line is relieved more pressure is delivered to the cylinders to counteract the rearward pull on the boom or tower due to the suspended weight of the masts and equalizer assemblies.
摘要:
A load handling device is disclosed having an improved swing drive assembly including a pivotally mounted swing drive pinion biased against a segmented ring gear by an actuator with a guide roller adjacent the pinion engaging a guide flange concentric with the ring gear to limit the maximum tooth engagement between the pinion and ring gear and thereby provide essentially constant backlash on the pinion gear regardless of eccentricities or other irregularities in the ring gear.
摘要:
A system for using a personal wireless communications unit or circuit with a wired telephone system is disclosed herein. In one embodiment, the system permits the user to provide telephone communication on a wired telephone system at a home using signal transmissions provided by a cellular phone instead of the conventional telephone lines. The system includes an interface which facilitates connection of the cellular phone to the system.