The present disclosure generally relates to a railroad track ballast tamping vehicle and associated methods of use, wherein the vehicle comprises: a rigid frame; a variable-displacement servo-pump operatively coupled to the vehicle; at least one linear hydraulic actuator operatively coupled to the frame at a proximal end of the at least one linear hydraulic actuator and comprising: at least one internal cavity for receiving hydraulic fluid from the variable-displacement servo-pump via a hydraulic hose; and an actuator rod passing through a first internal cavity and a second internal cavity of the at least one linear hydraulic actuator; and a tamping tool operatively coupled to a distal end of the at least one linear hydraulic actuator. A tamping pad associated with the tamping tool may be lowered into ballast underlying railroad tracks and between railroad track ties for performing ballast tamping operations.

A milling machine has a frame, ground engaging tracks that support the frame, a first actuator connecting the frame to a first track of the ground engaging tracks and a second actuator connecting the frame to a second track from the ground engaging tracks. The milling machine has an orientation sensor that determines an orientation of the frame. The milling machine has a controller that operates the first and second actuators to raise or lower the frame. The controller determines the frame orientation using the orientation sensor. The controller also determines a velocity error between actuator velocities of the first and second actuators based on the frame orientation and a target orientation of the frame. The controller determines a control parameter for the second actuator based on the velocity error and operates the second actuator using the determined control parameter.

A piston lock system having first and second cylinders, first and second pistons telescopically connected to the cylinders, and first and second piston locks. The piston locks are movable in a transverse direction within a planar region between the cylinders, between unlocked positions in which the piston locks are not located between the free ends of the cylinders and the free ends of the piston, and locked positions in which the piston locks are located between the free cylinder ends and the free piston ends. A control link is operatively connected to the piston locks, and configured to simultaneously move the piston locks between the locked and unlocked positions.

This invention relates to an automatic vehicle wash apparatus employing one or more rotary cloth or foam rubber brushes, and more particularly to the way how the rotary brush to vehicle surface contact is managed using one or more encoders connected to the rotating shaft of each brush and one or more programmable logic controllers (PLC). The encoders, recording the revolutions per minute (RPM) of each brush shaft, provide input to the programmable logic controller. If the RPM value is at or above the high RPM limit, the pivoted boom will move the brush toward the vehicle to achieve a desired brush-to-washable surface contact. If, on the other hand, the RPM value is at or below the low RPM limit, the pivoted boom will move the brush away from the vehicle to achieve a desired brush-to-washable surface contact.

A series train of symmetrical dual rod-end double-action hydraulic cylinders with a cross sectional area in a series of powers of 2. The cylinders have corresponding computer controlled valves. The cylinders are switchable into three states. One state of shortcutting 2 fluid ports, another state of driving towards each opposite direction of reciprocation and the third state of idling. In the cylinder train all same polarity ports of the valve assembly are connected by hoses or pipes to align towards the same orientation to enable synchronous reciprocal motion and train power output.

A milling machine may have a frame, first and second ground engagement members connected through respective, vertically adjustable leg columns to a front end of the frame, and third and fourth ground engagement members connected through respective, vertically adjustable leg columns to a rear end of the frame. Each vertically adjustable leg column includes a hydraulic cylinder connecting the frame and the associated ground engagement member. A milling drum is attached to the frame between the front and rear ends. At least one pair of the leg columns connected to the front end of the frame or the leg columns connected to the rear end of the frame includes an accumulator associated with each of the at least one pair of leg columns, a fluid conduit fluidly connecting a bore end of each of the hydraulic cylinders to the associated accumulator, and a control valve disposed in the fluid conduit and configured to control a flow of fluid between the hydraulic cylinders and the associated accumulators.

A three-rotational-degree-of-freedom connection mechanism required for a robot that can make motion similar to a human has a simple structure, and there is no restriction on motion within a movable range. The three-rotational-degree-of-freedom connection mechanism includes a joint connecting a second member rotatably to a first member with three rotational degrees of freedom including rotation around a torsion axis, three actuators each including variable length links having a variable length, and power sources for generating force changing the lengths of variable length links and three first-member-side link attaching units provided in first member and the second-member-side link attaching units provided on the second member such that variable length links having a twisted relationship with respect to a torsion axis exist in each state within a movable range of joint.

A piston lock system having first and second cylinders, first and second pistons telescopically connected to the cylinders, and first and second piston locks. The piston locks are movable in a transverse direction within a planar region between the cylinders, between unlocked positions in which the piston locks are not located between the free ends of the cylinders and the free ends of the piston, and locked positions in which the piston locks are located between the free cylinder ends and the free piston ends. A control link is operatively connected to the piston locks, and configured to simultaneously move the piston locks between the locked and unlocked positions.

The first piston of the first cylinder and the second piston of the second cylinder are connected so that the first piston and the second piston have the same displacement. The cross-section area of one side of the first piston is the smallest, and the cross-section area on the same side of the second piston is the third smallest. The two air chambers of the first cylinder and the two air chambers of the second cylinder are referred to as a first air chamber, a second air chamber, a third air chamber, and the fourth air in ascending order in the cross-section area. The control valve connects the air pressure source to the first air chamber, connects the second air chamber to the third air chamber, and opens the fourth air chamber to the atmosphere in the forward stroke.

An electro-hydrostatic drive for realizing a rapid movement during a rapid movement phase, a force-building movement during a force-building movement phase. The apparatus comprises a hydro-machine with variable volume and/or rotational speed, driven by an electric motor, for providing a volume-stream of a hydraulic fluid, a first cylinder with a piston chamber, an rod chamber, and a plunger rod, a reservoir, a pressure source, a relief valve, a check valve, a fluid connection between the piston chamber and the hydro-machine, a fluid connection between the rod chamber and the hydro-machine, a fluid connection between the piston chamber and the reservoir, a fluid connection between the rod-chamber-side port of the hydro-machine and the reservoir, a fluid connection, through the relief valve, between the reservoir and the pressure source. The relief valve is for pressure safety of the reservoir, and the check valve has a fluid connection from the pressure source to the rod-chamber-side port of the hydro-machine, during the rapid movement phase, a first part of the hydraulic fluid is piped through the fluid connection between the piston chamber and the hydro-machine and the fluid connection between the rod chamber and the hydro-machine, and a second part of the hydraulic fluid communicates through the fluid connection between the piston chamber and the reservoir, during the force-building movement phase, a first part of the hydraulic fluid is piped through the fluid connection between the piston chamber and the hydro-machine and the fluid connection between the rod chamber and the hydro-machine, and a second part of the hydraulic fluid is piped through the fluid connection between the rod-chamber-side port of the hydro-machine and the reservoir.