Material or article handling – Vertically swinging load support – Shovel or fork type
Reexamination Certificate
2000-02-17
2002-03-19
Batson, Victor (Department: 3671)
Material or article handling
Vertically swinging load support
Shovel or fork type
C414S912000, C037S406000
Reexamination Certificate
active
06357993
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a construction equipment implement and method of operating a hydraulically activated implement component and more specifically a skid-steer implement having a hydraulically controlled grapple component.
BACKGROUND OF THE INVENTION
Those familiar with the construction industry have long appreciated that construction equipment of the skid-steer front end loader type such as that shown in U.S. Pat. No. 3,231,114, when employed in a variety of different tasks are universally driven aggressively as they execute a multitude of construction chores. The aggressive manner in which skid-steer front end loader equipment is operated flows naturally from the very nature of the implements carried by the skid-steer loader arms. Typical implements include such apparatus as scarp buckets with grapple, single and double grapple buckets and manure forks with grapple to name a few. Each of these implements when secured to skid-steer front end loader arms on the front of the skid-steer loader engage either scrap, debris or other materials disposed or physically distributed along a surface upon which the skid-steer-loader is driven. The skid-steer loader with attached implement is normally driven in an aggressive fashion into materials sought to be moved. The momentum of the skid-steer loader and its attached implement coupled with the sudden reactive forces generated in the material to be moved by the impact of the implement and the material result in the implement being physically filled with the material. In order that the material that has been forced into the implement be held in place when the skid-steer loader moves to another location to deposit the material, the implement may include one or more hydraulically activated components that are pivotally mounted on the implement and move from an open unactuated position to a closed actuated position where the hydraulically actuated component forcefully grips the material between the component and implement to thereby secure the material in place during transit to a location where the material is to be deposited. When a skillful skid-steer loader operator is putting the skid-steer through its paces in the field, an observer of the skid-steer operator and his skid-steer loader will witness a symphony of coordinated activity of operator and skid-steer loader. As is well known, a skid-steer loader is a relatively small four wheel vehicle which is steered by braking or driving two wheels on one side of the vehicle while reversely driving the wheels on the other side of the vehicle. Two laterally spaced loader arms are mounted on the rear of the vehicle to swing upwardly and downwardly and, when the arms are swung downwardly their forward ends extend downwardly in front of the vehicle. A mounting plate is pivotally supported on the forward ends of the loader arms and normally support a construction implement such as a loader bucket. The very nature of the skid-steer loader as described above allows its operator to command the skid-steer loader to move forward and in reverse or to move in a tight circle about braked wheels of the loader while simultaneously opening or closing the hydraulically actuated component that cooperates with material forced into the implement. The most common manner in which the operator commands the hydraulically actuated component to open or close is to move a hydraulic control handle quickly from a fully open or unactuated position to a fully closed actuated position. The hydraulically activated component which is structurally heavy is therefore accelerated to significant velocities which induces momentum forces in the accelerated component. While the hydraulic actuation devices employed in moving the component are designed to move the component through a finite distance, the momentum, that is the mass and velocity of the component causes the component to continue its travel until it strikes a portion of the implement in what is called a hard stop. These hard stops cause the implement and the component to experience significantly high shock loading. The downside of this shock loading manifests itself in structural failures especially in bearings and bearing support structures of the implement and hydraulically actuated component.
To the question can an operator by careful attention to the movement of the hydraulic control lever avoid this shock loading, the answer is yes. In practice however a study of operator movement reveals that the operator may be simultaneously controlling a skid-steer loader movement and operation by the synchronized movement of both hands and feet at the same time. Accordingly normal skid-steer loader operation has the operator operating the loader at top speed to impact material to be carried by the implement and hydraulically actuated component that grips the material. It is not uncommon for the impact of the skid-steer implement with material to be moved to cause some of the material to pass physically through or by the component and implement resulting in damage to the hydraulic actuation apparatus or the skid-steer loader and/or its operator.
Typical of a work attachment or construction component of the type just described is shown in the F. P. Staken U.S. Pat. No. 5,565,885 ('885) issued Oct. 15, 1996. Of particular interest is a work attachment or component that includes a grapple hook mounted on the component by means of a set of two pairs of upstanding pivot brackets formed on the implement at opposite ends of the grapple hook. The grapple hook is caused to move from a fully open unactuated position to a fully closed actuated position by means of a pair of hydraulically actuated cylinders that are pivotally secured to each end of the implement and at the other end thereof to the grapple hook component.
When the grapple hook is moved quickly from an actuated position to an unactuated position severe shock loading is experienced in the pair of upstanding brackets and their respective pivot pins. It is this type of shock loading that eventually causes structural failure between the brackets and the implement of which they are a part. It is also to be noted that an open space between the pivot brackets at the opposite ends of the grapple hook allows ready passage of material being forced into the implement such that the material may pass through the implement and invade a front opening of the skid-steer cab and injure the skid-steer operator. The invention to be described hereinafter completely obviates shock loading problems of the nature experienced in the '885 patent while simultaneously protecting the skid-steer loader operator and the hydraulic cylinder actuation component of the implement.
SUMMARY OF THE INVENTION
Simply stated the principal object of the invention is to provide a method and apparatus that prevents shock load damage to a construction implement when a hydraulically actuated component thereof is quickly driven from a fully actuated to an unactuated position or vice versa.
More specifically the invention is directed to a skid-steer loader implement having a hydraulically actuated grapple component that includes an implement having first and second spaced apart pivot support structures and a hydraulically actuated grapple component pivotally secured to the second pivot support structure. A hydraulically actuated cylinder has one end of the cylinder pivotally secured to the first pivot support structure of the implement and is provided with a moveable piston integrally coupled to an output actuation rod that is pivotally secured at an end remote from the piston to the grapple component. The hydraulically actuated cylinder has supply/return ports adjacent the ends of the cylinder adapted to be alternately coupled to a high pressure hydraulic fluid supply or low pressure hydraulic fluid return. The hydraulically actuated cylinder has valve structure to hydraulically cushion movement of the piston and associated actuation rod as the piston moves past a supply/return port prior to being physically stopped at the ends of the
Batson Victor
Farmers' Factory Company
Leydig Voit & Mayer LTD
LandOfFree
Construction equipment implement and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Construction equipment implement and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Construction equipment implement and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2827867