Abstract: A mobile crane includes a boom extension assembly having a base boom section with a primary shell and a secondary formed shell attached thereto, which allows for selective strengthening along the length of the base boom section. Methods involve manufacturing a boom assembly including such a base boom section.

Abstract: A mobile crane includes a boom extension assembly carried alongside a telescoping boom assembly in a stowed position. The boom extension assembly includes a fly section with a first portion adapted for being connected to the head end of the boom assembly in an operative position while a second portion of the fly section adapted for being connected to the first portion remains in the stowed position. The first portion of the fly section may: (1) be shorter in length than the corresponding second portion of the fly section; (2) include sheaves for supporting a hoist line; (3) include a tapered end; or (4) be used in combination with two additional sections of the boom extension assembly. A related method includes connecting a first, shorter portion of a fly section to a head end of a telescoping boom assembly while a second portion remains in a stowed position.

Abstract: A locking and latching system for use with a telescoping boom assembly in a crane or other lifting device is provided. The system may include complementary devices for latching and unlocking a selected boom section for telescoping movement relative to a next-adjacent boom section using an extension cylinder. Preferably, the devices are activated in a predetermined sequence using a single motive device. The motive device may include a single cylinder for performing both the locking and latching function. The locking and latching cylinder may be axially aligned with the extension cylinder to create a relatively compact locking and latching system that easily fits within the confines of the innermost boom section in a conventional boom assembly.

Abstract: A locking and latching system for use with a telescoping boom assembly in a crane or other lifting device is provided. The system may include complementary devices for latching and unlocking a selected boom section for telescoping movement relative to a next-adjacent boom section using an extension cylinder. Preferably, the devices are activated in a predetermined sequence using a single motive device. The motive device may include a single cylinder for performing both the locking and latching function. The locking and latching cylinder may be axially aligned with the extension cylinder to create a relatively compact locking and latching system that easily fits within the confines of the innermost boom section in a conventional boom assembly.

Abstract: A suspension system for a heavy duty crane, excavator or the like is provided with a transverse rear axle and semi-independent suspension by hydraulic cylinders. The cylinders are pivotally attached adjacent the ends of the axle to allow oscillation in a traveling mode simulating a bolster, center pinned type system. The extend sides of the cylinders transfer hydraulic oil through an exchange line to accommodate true oscillation movement. In a working mode, locking valves block the flow of oil between the cylinders to establish a stabilized platform. A hydraulic/pneumatic accumulator communicates with the exchange line in the travel mode for cushioning of the ride. A third locking valve in a bypass return line communicating with the retract sides of the cylinders blocks the oil flow back to the reservoir in the working mode, but upon release by the control circuit is opened to communicate with the reservoir and maintain back pressure to enhance oscillation and prevent cavitation.

Abstract: A connecting system for aligning the fly lug of a strut on a boom extension for connection to the boom head shaft of a crane boom. The apparatus includes an offset jack screw extending through a threaded aperture in the boom head shaft parallel to the strut of the boom extension and a laterally extending tab affixed to the fly lug. The jack screw has a swivel pad at the head that contacts the tab. Manual adjustment to the jack screw is operative to move the lug so that a hole for a pin aligns with a mating hole in the head shaft. The face portion of the swivel pad universally mates with the operative face of the tab that extends at a 10.degree.-15.degree. angle normal to the axis of the strut to cancel the induced turning moment caused by the offset of said jack screw.

Abstract: A muffler assembly having a thermally-responsive valve mechanism is disclosed which facilitates draining of moisture from within the muffler assembly without compromise of its sound-attenuating characteristics. The muffler includes an outer muffler body which defines a water drainhole disposed at a relatively low portion of the muffler where water would otherwise collect. The valve mechanism comprises a valve member affixed to the muffler body in overlapping relation relative to the water drainhole. Notably, the valve member comprises material having a coefficient of linear thermal expansion which differs from that of the material from which the muffler body is formed, thus permitting the valve member to close and open the drainhole attendant to thermal expansion and contraction of the muffler body, respectively.