Abstract: A fluid control system (10) has a first fluid pump (12) for supplying pressurized fluid in interrupted series to first and second work elements (14,16). The first work element (14) in the series has priority which prevents simultaneous full power operation of the first and second work elements (14,16). A second fluid pump (24) is capable of supplying pressurized fluid to the second work element (16) only upon receiving a signal indicating that pressurized fluid from the first pump (12) is being directed to the first work element (14). The subject fluid control system (10) is especially useful with a tree harvesting machine where it is beneficial to propel the machine and at the same time rotate the upper structure.

Abstract: A shear blade assembly (10) on, for example, a tree harvester (12) has first and second blade portions (14,16)which are urged into opposite portions of a tree circumference to cut the tree. A desirable shape of the blade assembly (10) is a concave configuration which minimizes tree damage and efficiently distributes loads through the shear blade assembly (10). An improved method for making the concave shear blade assembly (10) includes cutting blade surfaces (42,44) on a blank (30) and leaving a web (50) between the surfaces (42,44), then depressing the blank (30) to form the desired shape and dividing the blank (30) along the web (50) to form the first and second blade portions (14,16). Making the surfaces (42,44) before shaping and dividing the blade portions (14,16) overcomes problems stemming from distortion of blades which are cut along a curvature following the step of obtaining the desired shape in the blade assembly (10).

Abstract: A brake release mechanism for a spring-loaded, normally applied vehicle brake releasable by system hydraulic pressure when said system is disabled includes a manual cut-off valve for isolating said brake from the disabled system and manual hydraulic pump means communicating with said brake for supplying fluid pressure thereto.Manual or pilot operated shunt means are provided for shunting a hydraulic motor associated with the brake to allow free turning thereof during towing.

Abstract: A linkage associated with a boom and stick arm of a vehicle includes struts mounted to the boom and stick arm, links mounted to the stick arm, an implement pivotally mounted to the stick arm, and a cylinder interconnecting the struts and links for providing that as the stick arm is moved relative to the boom, the implement maintains a chosen attitude.

Abstract: A vehicle has a tree shear mechanism mounted thereto, which is raisable and lowerable relative to the vehicle. The tree shear mechanism may also be tilted about a longitudinal axis of the vehicle so that with the vehicle on ground of one level and slope, and the tree to be sheared on another ground level and slope, the tree shear mechanism can be properly positioned for appropriate shearing of the tree.

Abstract: In a tree harvesting machine having a shear assembly, a delimbing assembly, a drive mechanism for moving a tree past the delimbing assembly, and a grapple arm for urging the tree into engagement with the drive mechanism and the delimbing assembly, a hydraulic control circuit including a pair of control valves disposed along a main fluid line providing communication between an upstream source of fluid under pressure and a downstream reservoir, one of the valves being selectively operable to divert fluid under pressure upstream to a grapple arm motor and simultaneously provide communication between the grapple arm motor and the line downstream to actuate or retract the grapple arm, and the other of the valves being selectively operable to divert fluid under pressure upstream to a shear motor and simultaneously provide communication between the shear motor and the line downstream to actuate or retract the shear assembly and to divert fluid under pressure upstream to a drive motor to actuate the drive mechanism w

Abstract: A tree-shear apparatus includes two blades, each having a spherical blade portion. The blades are pivotally mounted relative to a frame, with the pivot axes of the blades and the radii of the spherical blade portions being arranged to provide that a true spherical cut of a tree is achieved.

Abstract: A material handling apparatus having a stub boom provided with structure for connecting a fore boom thereto to form a two-piece boom, structure for selectively swingably positioning the stub boom, a work implement, and an improved joint structure for swingably connecting the work implement to the stub boom. The improved joint is defined by an adapter having a mounting portion and a joint portion swingably interconnected. Mounting structure is provided for cooperating with the stub boom connecting structure for mounting the adapter mounting portion to the stub boom, and mounting structure is provided for mounting the work implement to the joint portion of the adapter. A positioner is provided for selectively swingably positioning the joint portion of the adapter for correspondingly selectively positioning the work implement.

Abstract: A ripper of an earthworking apparatus includes a shank with a tapered, forwardly projecting lower end portion that has a blunt extremity, a detachable hollow shin protector which embraces the lower end portion of the shank, both to reinforce said lower end portion and to transfer some ripping forces to the upper portion of the shank which is stronger than the tapered lower end portion, and a one-piece detachable ripper tip which has a rearward mounting stub provided with spaced control surfaces that abut mating control surfaces on the shank and/or the shin protector to positively position the ripper tip and to transfer certain ripping forces through the shin protector to the upper portion of the shank.

Abstract: A bulldozer assembly comprises a pair of laterally spaced push arms pivotally mounted at their forward ends to a blade. A stabilizing member is secured to each of the push arms and the members are disposed rearwardly of the blade in disconnected relationship therewith. The inboard ends of the stabilizing members are pivotally connected together by a transverse pivot pin disposed one-half the distance between the ends of the push arms. In a first embodiment, the pivot pin is confined within the stabilizing members whereas in a second embodiment the pivot pin extends completely through the stabilizing members and into the push arms.

Abstract: A shear mechanism includes shear members pivotally mounted to a first frame, with a second frame movable relative to the first frame, and first and second links connected to the second frame. The first and second links are also connected to the first and second shear members, and first and second cylinders are connected with the second frame and the first and second links respectively, so that actuation of the cylinders in one direction moves the links to bring the shear members together, and actuation of the cylinders in the other direction moves the links to move the shear members apart, with the second frame moving relative to the first frame upon such movement of the first and second shear members.

Abstract: A trunnion ball and socket bearing assembly suitable for coupling the push arms of a bulldozer attachment to the sides of a tractor has a removable sleeve disposed coaxially on a trunnion shaft to define a spherical surface. Separatable bearing caps enclose the sleeve and have inner surfaces of spherical configuration to form a pivot joint which is capable of a limited amount of movement at right angles to the principal pivot axis. The replaceable sleeve fits against an annular shoulder on the trunnion shaft and is held thereon by a circular retainer member secured to the end of the trunnion shaft by bolts having heads which seat in counter bores in the retainer member. The sleeve may be heat treated to provide hardness while the trunnion shaft is separately treated to provide high strength thus providing an element which is more durable than a solid ball while being replaceable when necessary without requiring replacement of the entire trunnion.