Golf Hole Drilling Drive Shaft for Stable Cutting and Plug Ejection

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Solution Overview

Problem

Existing golf hole drilling apparatuses pose risks of injury to operators due to manual resistance against rotating forces and require complex mechanisms for vertical alignment and plug ejection, leading to potential damage to the green surfaces.

Innovation Solution

A golf hole drilling apparatus with a threaded drive shaft and non-threaded end portions for controlled axial movement of the cutter head, combined with a tread plate for stability and a reversible drive motor for easy plug ejection, allowing operators to drill and eject plugs with minimal manual effort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the operator manually resists the rotating force during drilling, then the cutter head can be controlled, but the operator increases the risk of injury and cannot maintain proper vertical alignment

Engineering Contradiction:
Improveoperator controlVSAvoidoperator injury risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A counterweight mechanism is introduced as an intermediary between the operator and the rotating cutter head. The counterweight automatically generates a counterbalancing force that offsets the rotating force, eliminating the need for manual resistance while maintaining control. This mediator device prevents operator injury by removing the direct harmful interaction between the operator and the rotating mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a complex clutch mechanism is used to ensure cutter head engagement, then drilling stability is improved, but the mechanism may slip out of engagement due to wear and spring tension reduction

Engineering Contradiction:
Improvecutter head engagementVSAvoidclutch mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The complex clutch mechanism with spring loading is extracted and replaced by a simpler direct engagement system. The cutter head is directly connected to the drive shaft through a rigid coupling that maintains constant engagement without relying on spring tension or clutch plates. This eliminates the wear and tension issues inherent in the original clutch design while maintaining reliable engagement.

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If the cutter head is pressed down into the earth with rotating force, then drilling efficiency is improved, but the green edges may be damaged and the cutter head may tilt

Engineering Contradiction:
Improvedrilling efficiencyVSAvoidgreen surface damage
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

A counterweight mechanism is implemented that generates an opposing force to balance the rotating pressing force of the cutter head. The counterweight automatically adjusts to maintain the cutter head in vertical alignment while it drills into the earth. This prevents tilting and distributes the force more evenly, reducing damage to the green edges while maintaining drilling efficiency.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

4Ease of operation

If a foot operated pedal is used for ejection, then the earth plug can be ejected, but added force is required if the plug sticks to the inner surface

Engineering Contradiction:
Improveplug ejectionVSAvoidejection force required
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The ejection mechanism is designed to be self-actuating through the reverse rotation of the drive shaft. When the operator reverses the rotation direction, the threaded connection between the drive shaft and ejection plate automatically generates the ejection force, pushing the plug out without requiring additional manual or foot pressure. The system uses its own rotational motion to perform the ejection function.

Inventive Principle:
Principle #25Self-service

5Productivity

If the cutter head rotates and is pressed down manually, then holes can be drilled, but the apparatus is heavy to lift and transport

Engineering Contradiction:
Improvehole drilling capabilityVSAvoidapparatus weight
Core Design Contradiction:
ProductivityVSWeight of moving object

Solution Approach 1:

The apparatus incorporates a retractable cutter head mechanism that allows the cutting component to be retracted into the housing when not in use. This dynamic configuration reduces the overall height and footprint of the apparatus during transport, making it easier to lift and move while maintaining full drilling capability when deployed.

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

The apparatus reduces operator injury risks and ensures precise, efficient drilling and ejection of plugs with improved working conditions, maintaining the integrity of the golf green surface.

Implementation Method 1

The drive shaft is a threaded shaft which is connected to the cutter head via a threaded coupling, where the cutter head is advanced relative to the tread plate when the drive shaft is rotated in one rotational direction and is retracted relative to the tread plate when the drive shaft is rotated in the opposite rotational direction

Methodology Applied
Scientific EffectScrew mechanism: Screw

Data Source

PatentEP4717874A1An apparatus and a method of drilling holes
Publication Date: 2026.04.01 GOLF & MACHINES APS
  • EP4717874A1 patent drawingFigure 1
  • EP4717874A1 patent drawingFigure 2
  • EP4717874A1 patent drawingFigure 3

AI summary

There is described an apparatus for drilling a hole, preferably in a golf green. The apparatus comprises a support frame, a moveable cutter head, a handle, a base, a tread plate, an ejection mechanism, a drive motor configured to power the operation of the apparatus and control means. A drive shaft connects the drive motor with the cutter head via a threaded coupling. The cutter head is advanced relative to the tread plate when the drive shaft is rotated in one rotational direction and is retracted relative to the tread plate when the drive shaft is rotated in the opposite rotational direction. The drive shaft is provided with a central threaded portion and a non-threaded end portion at each end of the thread. The non-threaded end portions act as slip couplings configured to allow a rotation of the drive shaft without axial movement of the threaded coupling whereby the axial movement of the cutter head is stopped. The control means is configured to reverse the rotating direction of the drive motor and thus also the rotational direction of the drive shaft.