Stapler Camshaft Mechanism for Variable Boosting and Magazine Access

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing staplers with variable boosting mechanisms face issues such as increased size due to the inability to open the magazine by rotating the handle, limited capacity for smaller staples like JIS No. 10 needles, and poor sliding due to restricted grease application in bearing parts.

Innovation Solution

A stapler design featuring a clincher unit, magazine unit, driver unit, and handle unit with a camshaft and cam groove mechanism that allows the magazine to be opened by rotating the handle, accommodates three JIS No. 10 needle staples, and includes a guide portion to restrict movement paths, along with a pusher system and grease storage to prevent poor sliding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a variable boosting mechanism is implemented with a closed long hole shape for shaft hole portion, then the boosting rate can be varied, but the magazine cannot be opened by rotating the handle and the device size increases

Engineering Contradiction:
Improvevariable boosting mechanismVSAvoidmagazine opening operation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The shaft hole portion is designed as a dynamic structure that changes its effective shape based on handle position. When the handle is in the standby position, the shaft hole has a closed long hole shape to provide variable boosting. When the handle is rotated to open the magazine, the shaft hole shape changes to allow the magazine to rotate freely, thus resolving the contradiction between maintaining variable boosting and enabling magazine opening.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the geometric parameters of the shaft hole portion dynamically. By making the shaft hole portion's shape and dimensions variable based on handle position, the system can switch between providing variable boosting (closed long hole shape) and allowing magazine opening (open shape), thus resolving the technical contradiction.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the shaft hole diameter and shaft portion diameter are made substantially the same, then the structure is simplified, but the grease application amount is limited and poor sliding occurs

Engineering Contradiction:
Improvebearing part structureVSAvoidsliding performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The invention applies local quality by creating a grease storage chamber in the bearing part with a specific local structure. The shaft hole portion is designed with a larger diameter than the shaft portion at certain locations to form this chamber, allowing concentrated grease storage at this specific location. This resolves the contradiction by maintaining simple overall structure while providing enhanced local grease storage capability to prevent poor sliding.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The grease storage chamber is designed to pre-store grease before it is needed for lubrication. The chamber accumulates grease in advance, and this stored grease is then supplied to the bearing surface during operation, ensuring continuous lubrication and preventing poor sliding even when the overall grease application amount is limited by the simplified structure.

Inventive Principle:
Principle #10Preliminary action

3Quantity of substance

If the magazine capacity is increased to accommodate more JIS No. 10 needle staples, then the number of staples increases, but the device size increases

Engineering Contradiction:
Improvenumber of staplesVSAvoiddevice size
Core Design Contradiction:
Quantity of substanceVSVolume of stationary object

Solution Approach 1:

The invention applies nesting by allowing the magazine to rotate within the device housing. The magazine is nested within the available space and can rotate to access staples. This nested configuration allows the magazine to accommodate more JIS No. 10 needle staples (increasing quantity) while utilizing the existing device volume efficiently, thus resolving the contradiction between increasing staple capacity and maintaining compact device size.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 efficient loading and operation of three staple bundles with reduced handle movement, maintains smooth sliding operations, and extends the stapler's durability by continuous grease supply to bearing parts.

Implementation Method 1

a camshaft portion provided to any one of the clincher unit and the handle unit; a cam groove portion provided to the other of the clincher unit and the handle unit

Methodology Applied
Scientific EffectCam mechanism: Cam

Implementation Method 2

grease, which is lubricant, may be applied to shaft holes of the bearing parts and the shaft portion so as to reduce the friction during rotation (sliding) between the shaft portion and the other components

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP4574339A1stapler
Publication Date: 2025.06.25 MAX CO LTD
  • EP4574339A1 patent drawingFigure 1~2
  • EP4574339A1 patent drawingFigure 3~4
  • EP4574339A1 patent drawingFigure 5

AI summary

A stapler includes: a handle unit that is connected to the driver unit by a transmission shaft part provided between the fulcrum shaft part and the driver, and moves the driver unit; a camshaft (23) provided in a clincher unit (2); a cam groove part (50d) that is provided in the handle unit 5, allows the camshaft (23) to enter, and has an open end portion on the clincher unit (2) side to allow the camshaft (23) to be inserted and removed; a guide protruding part (20g) provided in the clincher unit (2); and a guide recessed part (51a) that is provided in the handle unit (5) and restricts a movement path of the handle unit (5) with respect to the clincher unit (2).