Abstract: A telescopic boom is pivotally mounted on a frame of a vehicle and comprises telescopically disposed first, second, third and fourth sections. A double-acting cylinder has a rod thereof connected to the first section and a housing thereof connected to the second section. A first pulley is rotatably mounted on a forward end of the cylinder housing and a second pulley, having a larger diameter than the first pulley, is rotatably mounted on a rearward end of the cylinder housing. A first end of a cable is secured to the first section and is sequentially entrained over the first pulley, secured to the third section, entrained over the second pulley and has a second end thereof secured to a forward end of the first section. Thus, extension of the cylinder will function to extend the second section relative to the first section and simultaneously extend the third section at twice the linear speed as that of the second section.

Abstract: A shovel linkage for a hydraulic excavator includes boom rails having pivot means in one end for pivotal connection to an excavator and cross tubes extending between the rails near the pivot means and having pivot joints provided thereon for connection of actuating cylinders for the linkage in line with the cross tube and close to the pivot means whereby forces imparted to the linkage by the actuating cylinders will be directly through the center of the cross tube and very near the boom rail pivot means, minimizing bending moments in the linkage.The pivot joint includes a flat tab member provided on the cross tube and projecting outwardly along a diameter thereof, and a pin and ball connecting the bifurcated end of a hydraulic cylinder to the tab for limited rotation thereof. The pin is disposed substantially normal to the plane of the boom rails for unimpeded insertion and removal thereof.

Abstract: A shovel linkage for a hydraulic excavator or the like has spaced parallel boom link rails which are coplanar with associated spaced parallel stick link rails and pivotedly connected thereto by means of pivot joints provided on the ends thereof.Bucket stops are provided on a bucket attached to the stick and are arranged to contact the centers of the stick rails for greater strength.

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 hydraulic excavator having linkage providing for a front loading arrangement whereby the bucket opens away from the vehicle comprises power cylinders and linkage arranged to provide a balanced system providing maximum application of power and optimum use of power applied to the material-handling bucket. The power cylinders are connected to the linkage in a manner to utilize maximum leverage of the linkage when maximum power is needed.