Trackball Input Device Adjustable Friction Ring Cover

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing trackball input devices require complex control electronics for haptic feedback and are difficult to clean, with mechanics prone to failure, and users need adjustable frictional resistance for comfort.

Innovation Solution

A rotatable ring cover with protruding ring segments and a radially circumferential groove system allows for adjustable frictional resistance by changing the pretension on the trackball, enabling users to set comfortable rotational resistance through simple turning, and allows for easy cleaning and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If complex control electronics are used to generate active haptic feedback, then haptic feedback capability is improved, but device complexity and reliability deteriorate

Engineering Contradiction:
Improvehaptic feedback capabilityVSAvoidcontrol electronics complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces complex electronic control systems with a purely mechanical adjustment mechanism. The ring cover with locking lugs and grooves provides passive mechanical adjustment of the trackball's rotational resistance, eliminating the need for electronic actuators, sensors, and control circuits while still delivering adjustable haptic feedback.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The mechanical adjustment system is self-regulating through the interaction between locking lugs and grooves. When the ring cover is rotated, the locking lugs engage with grooves at different radial distances, automatically adjusting the pretension force on the trackball without requiring external power or electronic control.

Inventive Principle:
Principle #25Self-service

2Ease of repair

If the ring cover is detachably connected to allow cleaning and component replacement, then ease of maintenance is improved, but structural reliability deteriorates

Engineering Contradiction:
Improvecleaning and component replacement easeVSAvoidconnection reliability
Core Design Contradiction:
Ease of repairVSReliability

Solution Approach 1:

The device is segmented into detachable components: the ring cover can be separated from the housing, and the trackball can be removed from the housing. This segmentation enables easy cleaning and component replacement while maintaining reliable operation when assembled.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connection between the ring cover and housing transitions from static to dynamic. The detachable design allows the connection state to change between assembled and disassembled, enabling maintenance while providing sufficient mechanical stability during normal operation through the locking lug and groove engagement.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If locking lugs are pressed further by the groove in the direction of the trackball, then frictional resistance adjustment range is improved, but manufacturing precision requirements worsen

Engineering Contradiction:
Improvefrictional resistance adjustment rangeVSAvoidgroove and locking lug dimensional precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The invention adjusts the frictional resistance by changing the radial position parameter of the locking lugs relative to the trackball. The groove is designed with varying radial distance from the center, allowing the locking lugs to engage at different positions that correspond to different pretension forces on the trackball, thereby providing adjustable frictional resistance.

Inventive Principle:
Principle #35Parameter changes

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

Enables users to adjust trackball resistance easily, enhances user comfort, simplifies cleaning and maintenance, and reduces mechanical failures by allowing variable rotational resistance and easy detachment for component replacement.

Implementation Method 1

the frictional resistance between the trackball and the receiving opening accommodating it can be adjusted in a simple manner by turning the ring cover

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3112994B1Input device
Publication Date: 2018.09.19 RAFI GMBH & CO KG
  • EP3112994B1 patent drawingFigure 1
  • EP3112994B1 patent drawingFigure 2
  • EP3112994B1 patent drawingFigure 3

AI summary

In an input device (1) for converting manually generated rotational movements into electrical switching signals, in particular as a spherical trackball arrangement for computers, electric machine tools or the like, - comprising a housing (3) in which a receiving opening (4) is incorporated, the receiving opening having a semicircular inner contour adapted to receive the trackball (2), - wherein the trackball (2) rests on the inner wall (6) of the receiving opening (4) of the housing (3) and is rotatably mounted thereon, - comprising a plurality of sensors, pushbuttons, or the like provided in the receiving opening (4), which cooperate with the trackball (2) to detect its rotational movements and by which electrical switching or rotational movement signals can be generated, and - comprising a ring cover (9) by which the trackball (2) is held on the housing (3) and in the receiving opening (4),and whose inner diameter (10) is slightly smaller than the largest outer diameter (11) of the trackball (2), - the rotational movements of the trackball (2) should be able to be adjusted in a simple and quick manner, so that each user can adjust the frictional resistance of the trackball (2) to their liking. This task is solved by the fact that the ring cover (9) is rotatably mounted on the housing (3), that at least one ring segment (21) is provided on the ring cover (9), which projects from the ring cover (9) and, in the mounted state of the ring cover (9), bears against the outer surface (7) of the trackball (2) and against the inner wall (6) of the receiving opening (4), at least partially, and that a radially circumferential groove (22) is machined between the inner wall of the housing (13) and the outer wall of the receiving opening (4).the distance of which to the center point (14) of the receiving opening (4) in the direction of rotation of the ring cover (9) is of different sizes and that at least one locking lug (16,17) is formed on the respective ring segment (21) which is inserted into the groove (22).