Fork Arm Contact Elements for Automatic Battery Charging

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Solution Overview

Problem

Existing battery-powered industrial trucks require time-consuming manual charging processes, especially during opportunity charging, due to the need for manual disconnection and reconnection of battery charging systems, which is inefficient and not suitable for work breaks.

Innovation Solution

The contact elements are arranged on the underside of fork arms or wheel arm extensions, allowing for automatic charging without the need for manual intervention, enabling a large ground clearance and simplified installation in limited spaces, with resiliently supported contact elements ensuring sufficient contact pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual disconnection and reconnection of battery charging systems is used, then charging can be performed, but the charging process becomes time-consuming and inefficient

Engineering Contradiction:

Improvecharging speedVSAvoidcharging time

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The charging system performs automatic connection and disconnection without manual intervention. The vehicle-side contact elements on the fork arms automatically engage with the ground-side contact elements when the forklift approaches the charging station, and automatically disconnect after charging completes, eliminating manual plug operations

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The contact elements are pre-positioned on the fork arms and ground in aligned positions. The vehicle-side contact elements are mounted on the fork arms at positions that automatically align with the ground-side contact elements when the forklift approaches the charging station, enabling immediate automatic connection without manual intervention

Inventive Principle:

Principle #10Preliminary action

2Extent of automation

If vehicle-side contact elements are arranged on the underside of fork arms, then automatic charging is enabled and ground clearance is maintained, but the contact elements must be protected from damage

Engineering Contradiction:

Improveautomatic chargingVSAvoidcontact element protection

Core Design Contradiction:

Extent of automationVSReliability

Solution Approach 1:

The vehicle-side contact elements are nested within the hollow structure of the inverted U-profile fork arms. The contact elements are received in recesses formed in the fork arms, providing protective enclosure while maintaining electrical functionality. This nesting arrangement protects the contact elements from external damage during operation

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The resiliently supported contact elements incorporate spring mechanisms that provide cushioning and shock absorption. The resilient support system absorbs impact forces and mechanical stresses that occur during automatic engagement and disengagement, preventing damage to the contact elements before failure can occur

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Area of stationary object

If contact elements are arranged on the underside of fork arms, then installation space is limited, but sufficient contact pressure must be maintained

Engineering Contradiction:

Improveinstallation spaceVSAvoidcontact pressure

Core Design Contradiction:

Area of stationary objectVSForce

Solution Approach 1:

The contact pressure is locally optimized at the engagement point between vehicle-side and ground-side contact elements. The resilient support system concentrates the necessary contact force at the small contact interface, while the overall structure maintains compact dimensions. The spring mechanisms provide localized high contact pressure in the limited space available on the fork arm underside

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The contact pressure is dynamically maintained through resilient spring support rather than rigid fixation. The spring mechanisms automatically adjust the contact pressure based on engagement conditions, maintaining sufficient electrical contact force while accommodating variations in positioning and wear within the limited installation space

Inventive Principle:

Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution reduces the time required for charging, eliminates the need for a separate drive system, and allows for efficient opportunity charging during work breaks, enhancing operational efficiency and convenience.

Implementation Method 1

resiliently supported contact elements ensuring sufficient contact pressure

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP2090457B1Battery-operated industrial truck including a contacting system

Publication Date: 2012.07.25 JUNGHEINRICH AG

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Figure 5~6

AI summary

The system has two contact elements (26, 28) at a battery-powered industrial truck and cooperating with two contact elements of a charger mounted at the ground. The contact elements at the truck are arranged at a lower side in a front end region of fork tines and/or wheel arm extensions and/or fork arms (20, 22). The contact elements at the truck are arranged adjacent to each other at the fork tines, wheel arm extension and/or fork arms. The contact elements are mounted between legs at a lower side of a U-shaped bar of the fork tines, wheel arm extensions or fork arms.