IP Verse

Shovel Lifting System And Method

Patent No. US11851309 (titled "Shovel Lifting System And Method") was filed by 8082464 Canada Inc on Apr 30, 2018.

What is this patent about?

’309 is related to the field of lifting heavy machinery, specifically mechanical or electrical shovels, for maintenance purposes. The background acknowledges the challenges and risks associated with existing methods, such as one-sided lifts or integral lifts without proper control, which can lead to instability, ground pressure issues, and potential accidents. The patent addresses the need for a safer and more efficient system for raising these large machines.

The underlying idea behind ’309 is to provide a controlled, multi-point lifting system that raises a shovel as a whole while maintaining its level. This is achieved by using a combination of strategically placed lifting units (jacks) under the carbody and counterweight, coupled with a control system that monitors and adjusts the lifting force at each point. A key aspect is keeping the shovel's dipper on the ground during the lift to manage the center of gravity.

The claims of ’309 focus on a method and apparatus for lifting a shovel. The method involves positioning lifting units under the carbody and counterweight, extending these units to contact the shovel, lowering the dipper to the ground, and then initiating a controlled lifting operation. The apparatus includes adjustable lifting units, particularly at the counterweight, and a control unit with level detectors to maintain the shovel's level during the lift.

In practice, the system uses a programmable logic controller (PLC) to manage the hydraulic jacks. The PLC receives input from level detectors attached to the shovel and pressure sensors at each jack. This allows the system to compensate for uneven ground settling or hydraulic failures by adjusting the pressure at individual jacks, ensuring a smooth and level lift. The adjustable height stands under the counterweight are crucial for accommodating different shovel models and preventing interference during setup.

The differentiation from prior approaches lies in the integrated control system and the strategic placement of lifting points. Unlike previous methods that rely on manual operation and can lead to imbalances, ’309 automates the lifting process, minimizing human error and ensuring stability. The use of adjustable stands and a pre-assembled skid further streamlines the setup process, making it faster and safer to lift shovels for maintenance.

How does this patent fit in bigger picture?

Technical landscape at the time

In the late 2010s when ’309 was filed, lifting heavy machinery such as mechanical shovels for maintenance was typically implemented using hydraulic jacks. At a time when Programmable Logic Controllers (PLCs) were becoming more prevalent in industrial automation, systems commonly relied on manual operation or simpler control circuits rather than sophisticated feedback loops for maintaining level during lifting. When hardware or software constraints made precise, real-time adjustments to multiple jacking points non-trivial, ensuring even lifting and preventing stress on the machinery was a significant engineering challenge.

Novelty and Inventive Step

The examiner approved the application after making minor corrections to the claims. These corrections included replacing "the load" with "a load", "detector" with "detectors", "when movement" with "when the movement", "during the entire lifting" with "during an entirety of the lifting", "inserting shim" with "inserting the shim", "block comprises" with "blocks comprise", and similar grammatical and phrasing adjustments to claims 38 and 43.

Claims

There are 26 claims in total, with independent claims numbered 1, 19, and 26. The independent claims are directed to a method and apparatus for lifting a shovel. The dependent claims generally elaborate on specific features, components, and operational aspects of the lifting method and apparatus.

Key Claim Terms New

Definitions of key terms used in the patent claims.

Term (Source)Support for SpecificationInterpretation
Adjustable height stands
(Claim 19, Claim 26)		“According to a still further broad aspect, there is provided a method of safely lifting a shovel as a whole above ground while maintaining the level throughout the entire operation. The method comprising: i) Preparing ramps to provide an initial raise of the shovel using, for instance, common wooden mats and dirt from the surrounding area, v) Attaching removable level detectors to the shovel pointing downward to the ground using commonly available means such as magnetic supports”Stands that support the second set of lifting units under the counterweight, and can be moved between retracted and extended positions, and mechanically locked in the extended position.
Adjustable skid
(Claim 19)		“According to a still further broad aspect, there is provided a method of safely lifting a shovel as a whole above ground while maintaining the level throughout the entire operation. The method comprising: ii) Locating a plurality of jacking points (e.g. 3 pairs) and a hydraulic power & control unit on the ground at the planned locations to fit the specific shovel to be lifted”A structure comprising skid plates adjustably mounted to transversal beams, where the first set of lifting units are adjustably mounted, allowing for variable positioning of the lifting units.
Force applying points
(Claim 1, Claim 19, Claim 26)		“In accordance with a further general aspect, there is provided a method of lifting a shovel having a carbody, a dipper, and a counterweight, the method comprising: a) setting up a lifting system at a given lifting site, including adjusting the relative position of a set of lifting units to match corresponding force applying points on the carbody and the counterweight, the lifting units being operatively connected to a control unit”Specific locations on the carbody and counterweight where the lifting units exert force to lift the shovel.
Level detectors
(Claim 19, Claim 26)		“In accordance to another aspect, the PLC uses field data such as: Distance measurements using level detectors attached to the shovel in a predetermined pattern (e.g. a square pattern) such as: front left, front right, rear left and rear right”Devices operatively connected to the control unit, used to measure the level of the shovel during the lifting operation.
Lifting units
(Claim 1, Claim 19, Claim 26)		“There is described herein an apparatus and a method to lift or raise heavy machinery. The apparatus coordinates the lifting of the heavy machinery so that it can be raised with respect to a ground surface. In so doing, the apparatus provides clearance so that vehicles and maintenance crews can access the lower ends of the heavy machinery, and suspends the heavy machinery at an elevation while the maintenance operation is being performed.”Devices used to raise the shovel, positioned to match force applying points on the carbody and counterweight.

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US11851309

8082464 CANADA INC
Application Number
US16606311
Filing Date
Apr 30, 2018
Status
Granted
Expiry Date
Nov 8, 2040
External Links
Slate, USPTO, Google Patents