Abstract: A boat lift that may have a first worm screw operably connected to the drive shaft defining an axis of rotation aligned with the drive shaft and operably contacting a first worm gear, the first worm screw and the first worm gear defines a first lifting stage. The boat lift may also have a second worm screw operably connected to the first worm gear and operably contacts a second worm gear, the second worm screw and the second worm gear defines a second lifting stage. The boat lift may have a tapered roller bearing assembly that operably engages the second worm screw, the tapered roller bearing assembly has a first tapered roller bearing secured at a first location proximate a first end of the second worm screw and a second tapered roller bearing secured at a second location proximate a second opposing end of the second worm screw.

Abstract: A lifting device includes a drive, a speed change gear device arranged above the drive and configured to be rotatable by means of the drive, a transmission device connected to the speed change gear device and a lifting mechanism fixed in the transmission device, and the speed change gear device is fixed to a side wall of the transmission device. Under an action of the drive and a speed change of speed change gear device, a gravity of a weight suspended on the lifting device is converted, so that the weight is lifted under a small force. The lifting device can also be driven via an electric hand tool. In addition, a first transmission device and a second transmission device are provided with a safety device to lock the lifting device when reaching a top, so as to prevent the lifting device from slipping to cause injuries.

Abstract: The present invention relates to a rope grab arrangement comprising a rope grab for advancing a rope, the rope grab arrangement being configured to provide an increased friction between the rope grab and the rope for allowing use of multitude of different types of ropes. The invention also relates to a portable power driven arrangement comprising such a rope grab arrangement.

Abstract: The invention provides a chain wheel part comprising a center about which the part is adapted to rotate in use, and a plurality of chain link receiving pockets. Each pocket is shaped such that a first end of a chain link received in the pocket in use is nearer the center of the wheel than a second end of the chain link. The invention also provides a chain wheel including two such chain wheel parts.

Abstract: The actuator uses reinforced polyurethane timing belts as a flexible rack member mounted to the slide-out room and a pinion assembly mounted at the top and bottom of the slide-out opening of the main compartment. A pair of timing belts are mounted at the corners of the slide-out room top and floor, each running longitudinally to the direction of the slide-out movement. Each pinion block includes a pinion and two idle rollers. The timing belts pass through the drive block being trained around the pinion between two idle rollers in a serpentine fashion. A reversible electric motor, which is operatively connected to all four pinion blocks, simultaneously turns the pinions to propel the timing belts through the pinion blocks thereby extending and retracting the slide-out room through the slide-out opening.

Abstract: A chain block with a drive motor (2) and with a transmission (3), connected to the drive motor (2) at the take-off side, with a transmission output shaft (4), on which a chain wheel (5) is rigidly arranged for pulling a chain. In order to create a compact chain block, the chain wheel (5) faces the drive motor (2) at its take-off end face (19) and the outer circumference of the chain wheel (5) reaches into the imaginary extension of the outer contour of the drive motor (2).

Abstract: A storage platform and lift apparatus comprises a plurality of platforms; four cables; a plurality of elongated brace members; four elongated vertical members, each having a plurality of apertures extending therethrough; and a drive axle. A pulley wheel is rotatably coupled to two vertical members, while the other two vertical members support a drive axle which contains the four cables. A plurality of brace members support the vertical members in an upright, stable position. Upper and lower gear assemblies, in combination with the four cables extending outwardly away from the drive axle and coupled to the platforms, provide means to raise and lower the platforms to any desired height for either short- and long-term storage of machinery, equipment, and the alike.

Abstract: A watercraft lifting apparatus utilizing a lifting beam vertically movable within a frame preferably including pile members defining a watercraft receiving slot. The lifting beam is vertically movable to contact preferably the lower surface of the watercraft for moving it upwardly. The movement of the lifting beam is powered by a main drive connected through the lifting apparatus by two winching and cable devices. First an outer winch powers retraction and extension of an outer cable connected through a pulley configuration to the distal end of the lifting beam. Also an inner winching device is operable to extend and withdraw an inner cable operatively connected through a pulley configuration to the proximate end of the lifting beam to assure that the lifting beam is lifted vertically in a horizontal orientation to facilitate lifting of the watercraft such as for cleaning and/or storage thereof.

Abstract: A low-profile lifting apparatus (10) for hoisting and moving objects along an I-beam (12), comprising a frame assembly (20), a drive system (44), a pulley assembly (56), and a hoist assembly (66). The drive system (44) includes a first drive roller (48), and a second drive roller (49) operatively connected to each other and positioned on opposite sides of the web (14) to drive the lifting apparatus (10) along the lower flange (16). The drive mechanism (50) includes a pulley chain (62) that is manually pulled by an operator to rotate the drive shaft (60) and the attached drive rollers (48) and (49). A block (74) has a hook (76) positioned laterally on one side of the lateral centerpoint (82) nearest the chain hoist (68).

Abstract: Drawworks transmission shifting apparatus is described that provides an arrangement of control valves, cylinders, clutches and brakes which permit the rig operator to shift the drawworks transmission into the desired setting and to lock the transmission in those positions by the use of remotely controlled pneumatically powered cylinders.

Abstract: Drawworks, having a single outboard brake on the drum shaft at the driller side of the drawworks instead of the pair of brakes conventionally provided at the drum ends, whereby the brake is more readily accessible for service and repairs than are the brakes of conventional apparatuses.

Abstract: Separate torque converters are selectively clutched to the hoist and drag drums of a dragline machine with a selectively engageable clutch providing a power interlock of the output of both torque converters to either one of the drums as desired. The application and control of torque from the two torque converters to the hoist drum is in parallel and to the drag drum is in series progressive, i.e., the drag converter being engaged first and going from zero to maximum while the hoist converter goes from zero to about fifty percent of capacity as the drag converter reaches maximum. The reserve torque in the hoist converter may be selectively applied to the hoist drum to step the drag bucket up if the drag drum approaches a stall condition. The hoist converter may also be selectively engaged to apply a predetermined hold back force during bucket lowering. Another clutch may be engaged to interlock the two drums together for joint operation by the hoist converter.