Abstract: A shovel linkage for a hydraulic excavator includes a cross tube having pivot joints, and actuating cylinders for the linkage connected to said pivot joints thereon whereby forces imparted to the linkage by the actuating cylinders will be directly through the center of the cross tube, avoiding bending moments in the linkage.The cross tube has an internal diametrical member in line with the pivot joints and the actuating cylinders to withstand and transmit the forces imparted by the actuating cylinders.

Abstract: A horizontally rotatable and vertically elevatable power boom is disclosed. The boom includes a link providing increased lifting torque about the boom hinge pin and the boom assembly is designed for minimizing the head room requirements for the vacuum machine without sacrificing payload capacity. The link also permits the boom to be locked down hydraulically for traveling.

Abstract: In an articulated boom having a platform and comprised of upper and lower booms respectively, there are hydraulic actuators controlling the movements of the upper and lower booms. Control means are necessary in association with the lower boom to control its rate of movement, slowing such rate of movement as the lower boom approaches its retracted, or full rest, position. A position responsive valve permits unimpeded fluid pressure access to the actuator for lowering the lower boom at its regular rate until the lower boom reaches a critical angle as it approaches horizontal position, at which time the valve prevents further fluid access to its associated hydraulic actuator. Thereafter, a position responsive valve and a pressure reducing valve reduce the rate of descent of the lower boom until the lower boom is fully retracted to its rest position.

Abstract: A system for erecting elevated floors where a first support floor with a drawworks thereon is connected to one end of a base structure by two pair of parallel spaced pivotable links and a second support floor is coupled to the opposite end of the base structure and by two pair of parallel spaced pivotable links. In accordance with the invention a strong back is erected about midway of the length of the base forming a rigid frame and supporting elevated sheaves at each side of the base structure. A pair of cables are adapted to pass over said sheaves, one on each side of said base structure and connect first to said first floor for erection and then to said second floor for erection.

Abstract: A lifting boom having three telescopic sections. A hydraulic ram has the piston rod free end connected by a horizontal pin movable in guide slots at the rear of the base section. A deflection limiter is axially slidable on the piston rod, and is less high then the base section. The rear of the ram cylinder is pin connected by horizontal pins to the mid section, and has a transverse ram cylinder plate attached to it. Pull rods are connected to the deflection limiter and pass forwardly through the transverse plate, having detents at their forward ends beyond the transverse plates. A pair of chains extends from the base section forward and around sprockets at the rear of the mid section, being attached to the rear of the fly section, a further chain extending thence forwardly and around a sprocket on the front end of the ram cylinder, and thence rearwardly to an anchor on the base section; the ram sprocket has a roller portion which rolls on the fly section bottom plate to support the ram cylinder.

Abstract: An electro-hydraulic control system to enable either simultaneous extension or retraction of all boom sections in a telescopic crane boom or independent extension or retraction of one or more individual boom sections comprises a valve assembly, including solenoid-operated extend and retract valves, on each boom section cylinder; a manually operable three-position (neutral, extend, retract) main control valve for connecting the valve assemblies to a pressurized fluid source and to a reservoir; a relay for energizing all solenoid valves simultaneously when the main control valve is operated to extend or retract positions to thereby effect simultaneous extension or retraction, respectively, of all boom sections; and manually actuatable selector switches, one for each movable boom section, which, when any one selector switch is actuated while the main valve is operated, override the relay and energize only the solenoid valves in a selected valve assembly thereby enabling independent extension or retraction of a s

Abstract: Mobile lifting equipment having a wheeled vehicle with a frame. The boom structure is mounted on the frame for rotation about a vertical axis, raising and lowering the same about a horizontal axis and for extension and retraction with respect to the vehicle. The boom structure includes an outer boom and an inner boom which is mounted for telescoping movement in the outer boom. First and second extension cylinders are carried by the outer boom for extending and retracting inner boom with respect to the outer boom. An elevation cylinder is connected to the outer boom and is provided for raising and lowering of the boom structure. An elevation control is provided for supplying hydraulic fluid to the elevation cylinder. Piping is provided for connecting the elevation cylinder to one of the first and second extension cylinders so that extension of said one of said first and second extension cylinders is limited by the amount of hydraulic fluid which has been supplied from the elevation cylinder.

Abstract: A telescopic boom, for portable cranes, having one or more hydraulically operated telescopic slides, and one or more mechanically operated telescopic slides. The extension or retraction of the mechanically operated telescopic slide is effected by means of a detachable retaining rod, one end of which is connected with the non-telescopic main boom by means of a bolt inserted transversely therethrough. The other free end of the retaining rod is provided with a pressure piece, for maintaining the boom in some of its positions during extension thereof, and a tensioning device, which is located 180.degree. opposite from the pressure piece, for maintaining the boom in some of its positions during retraction thereof. A plurality of slots are arranged along the mechanically operated telescopic slide transverse to the direction of operation. These slots respectively cooperate with a cam of the pressure piece or with a stop cam of a pawl during extension and retraction of the telescopic slide.

Abstract: To facilitate transferring a massive crane boom from a regular crane carrier vehicle to an independent transport trailer, pivot pins for the rear ends of boom lift cylinders are held removably in journal boxes which are recessed into the crane turntable and are normally held captive in the recesses by shiftable locking dogs adapted to be extended over the tops of the journal boxes and to be retracted therefrom. The locking dogs are operated by turntable mounted power cylinders and safety means is provided to block accidental retraction of the locking dogs during normal crane usage.

Abstract: A telescopic boom for movable cranes with at least one hydraulically operable telescopic slide and with at least one mechanically operable telescopic slide. The pushing out movement and the retracting movement of the mechanically actuated telescopic slide is effected by means of a holding bar having a free end portion provided with a pressing or pushing member and with a pulling member offset by 180.degree. with regard to the pressing or pushing member. The other end of the holding bar is provided with a transverse bolt for engagement with a bearing on the at least one hydraulically operable slide. The mechanically operable telescopic slide is provided with cams extending transverse to its longitudinal direction of movement for cooperation with the holding bar.

Abstract: A wheeled, self-propelled tractor has a percussion tool or hammer mounted on its forward end and an impact transmitting means carried on the tractor below the hammer. The impact transmitting means comprises a metal frame having a strong rigid top plate that is struck by the hammer and a downwardly opening cavity in which wood timbers are mounted to transmit the impact from the plate to a cemetery marker. Repeated blows to the marker applied through the impact transmitting means will drive the marker into the ground until it is flush with the ground surface where it will not interfere with mowing. The frame is fastened on the vehicle by a suspension system that includes tension springs which keep the wood timbers in a horizontal plane but permit the frame to move downwardly each time it is struck by the hammer.

Abstract: A crane having a multisection telescopic boom is disclosed herein. The multisection boom is designed so that the intermediate and forward sections can be moved rearwardly with respect to the base section to decrease the overall length of the crane for transportation purposes.

Abstract: This invention relates to a method of and apparatus for erecting a vertical mast.In the invention a mast balanced by tensioned guys is erected while maintaining the guys in their tensioned condition.

Abstract: A street lighting column has upper and lower sections hinged together in such manner that the upper section can be lifted by a double-acting piston and cylinder unit connected between the column sections to a position in which it is free to pivot relative to the base section. The hinge is provided with a support plate adapted to be turned to a position in which it cooperates with a lug on one of the column sections so as to support the upper column section in its raised pivotal position when the direction of action of the piston and cylinder unit is reversed, thus automatically effecting pivoting of the upper section to a position in which it is reachable from the ground.

Abstract: An extensible cantilever boom assembly, for a mobile crane, has telescopically interfitting box-like boom sections, that include web or side plates of uniform thickness. These plates are shaped to provide increased stiffness, and openings are provided within some of the plates to reduce the plate weight, so that the load carrying capacity of the boom is increased. A plurality of shaped portions are formed within the plates, at locations intermediate the top edges and the bottom edges of the plates. These plate portions are spaced laterally from the parallel planes that define the side surfaces of the plates, at the junctures of the side surfaces with the top and bottom edges. The shaped portions, located at longitudinally spaced intervals, are aligned in a row that extends longitudinally of the plate. Each shaped portion has a regular geometrical pattern that forms a laterally projecting protuberance on one side of the plate and a corresponding depression on the opposite side of the plate.

Abstract: There is disclosed a telescoping boom with first and second motors, each connected between adjacent boom sections to extend and retract one boom section with respect to the other. Each motor has a piston slidably received in a cylinder to define an extend chamber on one side of the piston and a retract chamber on the other side thereof. Each piston has a rod extending from the cylinder which has two passages therein, one communicating with the extend chamber and the other communicating with the retract chamber. A control valve has a first portion for control of the first motor and a second portion for control of the second motor. The hydraulic passage between the retract chamber of the second motor and the second valve portion includes the retract chamber of the first motor. The hydraulic passage between the extend chamber of the second motor and the second valve portion, and only that passage, passes over a reel between said members.

Abstract: A tower crane and method of climbing the crane. The tower of the crane is initially stabilized at an elevated location, and the tower is released from a base frame supporting its base and elevated to place its base on an upper frame, the base frame is then elevated, and the tower is then dropped to place it on the newly positioned base frame with the upper frame then used to laterally stabilize the tower with the crane in operative condition.

Abstract: An improved boom includes a slider assembly for use in supporting telescoping sections of the boom for movement relative to each other. An articulated slider assembly embodying the invention includes a rocker member which is pivotally mounted on one section of the boom. A pair of slider block assemblies are pivotally mounted on the rocker member and slidably engage a supported section of the boom at spaced apart locations. Deflection of the supported boom section is compensated for by pivotal movement of the slider block assemblies relative to each other. A spring type slider assembly forms another embodiment of the invention and has a flexural rigidity such that the deflection of the spring type slider assembly matches the deflection of a supported section of the boom under the influence of an operating load to provide for the transmittal of a uniform bearing load between the supported boom section and slider assembly.

Abstract: A drill mast support assembly having a drill mast pivotable between a drilling and a non-drilling position and including elongated rigid brace means for stabilizing the mast in the drilling position. The brace means are connected to the mast by support means which provide for a compact assembly when the mast in the non-drilling position and permit the brace means to be automatically positioned as the drill mast is moved to the drilling position. Lock means are further provided for preventing relative movement between the mast and the brace means when the mast is in the drilling position.

Abstract: An extendible tower is disclosed and includes a plurality of nestable tower sections that may be raised from a telescoping, nested position to an extended position and support a load thereat. A plurality of inverted hydraulic cylinders are located within the tower sections and are also nestable in a collapsed position. Upon receipt of hydraulic pressure, the cylinders move upwardly and extend the nested tower sections. In this regard, the hydraulic cylinder group is secured at opposite ends to a base and to the upper tower section with no securement intermediate along the length thereof. Each hydraulic cylinder and each tower section is provided with means to couple the particular section or cylinder to the next adjacent section or cylinder so as to permit continued raising thereof.

Abstract: A stop lock assembly for a tower mounted on a platform and pivoted thereon whereby the tower is adapted to be raised from a horizontal position to a vertical, erected position. Stop members are operatively connected between the platform and the tower to limit the pivotal movement of the tower to the erected position and to hold portions of the platform and tower in alignment for the reception of locking pins extending therebetween for holding the tower in the erected position.