Clamping Device with Angled Drive Shaft for Bolt Tensioning

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Solution Overview

Problem

Conventional clamping devices struggle to operate in cramped spaces due to limited space for the gearbox and difficulty in attaching a suitable driving tool, especially with threaded bolts close together, where the axis of rotation of the drive shaft intersects the longitudinal center axis of the piston, limiting the force transmission to the nut.

Innovation Solution

A clamping device with a gear arrangement where the axis of rotation of the drive shaft is tangential and spaced from the longitudinal center axis of the piston, allowing for a more accessible and comfortable adjustment of the nut using an obliquely or transversely arranged drive shaft, with a bevel gear system enabling rotation transmission through intermeshing toothed elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the axis of rotation of the drive shaft intersects the longitudinal center axis of the piston (conventional arrangement), then the device structure is simple, but the device cannot be used in cramped spaces and the engagement structure is difficult to access

Engineering Contradiction:
ImproveAccessibility of engagement structureVSAvoidGearbox arrangement
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The drive shaft's axis of rotation is positioned at an angle (specifically 90 degrees) to the longitudinal center axis of the piston, rather than intersecting it. This spatial reconfiguration allows the engagement structure to be accessed from a different direction, enabling operation in cramped spaces where the conventional intersecting arrangement would be inaccessible.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Force

If the drive shaft axis intersects the piston center axis, then the mechanical transmission path is direct, but the force transmission to the nut is limited in cramped situations

Engineering Contradiction:
ImproveForce transmission to nutVSAvoidAccessibility for applying force
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

By orienting the drive shaft at an angle to the piston axis, the engagement structure becomes accessible from a more favorable position that allows for effective application of force. The bevel gear system transmits this force efficiently despite the angular arrangement, overcoming the limitations of cramped assembly spaces.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of operation

If a hand wheel with bevel gear teeth is used for tightening the nut, then the nut can be adjusted, but the force transmission is limited by manual accessibility and grip

Engineering Contradiction:
ImproveManual accessibilityVSAvoidForce transmission to nut
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The hand wheel mechanism is replaced with a drive shaft featuring an engagement structure (such as a square drive or hexagonal drive) that accepts external driving tools. This substitution allows for more effective force transmission while maintaining accessibility, as powered tools can be applied to the engagement structure rather than relying on manual grip on a hand wheel.

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

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 operation in situations where conventional devices cannot be used, providing improved accessibility and reduced frictional forces during nut tightening or retightening by allowing the use of a driving tool from a more favorable position, enhancing the usability in tight assembly scenarios.

Implementation Method 1

a gear arrangement for adjusting the nut, with components of the gear arrangement being a driver element acting on the outside of the nut and a drive shaft, the axis of rotation of which is at an angle of more than 0° and less than 180°, preferably at an angle of 90°, to the longitudinal central axis of the piston

Methodology Applied
Scientific EffectGear: Gear

Data Source

PatentEP2821182B1Clamping device for stretching a threaded bolt
Publication Date: 2017.09.06 ITH
  • EP2821182B1 patent drawingFigure 1~2
  • EP2821182B1 patent drawingFigure 3a~4

AI summary

A clamping device for stretching a threaded bolt by pulling on its threaded end section (A), comprising a support tube (2) surrounding the threaded end section (A) and a nut (4) screwed onto the threaded end section (A), a cylinder arranged in extension of the support tube (2) with at least one piston (7) movable longitudinally therein and connectable to a hydraulic supply, an interchangeable bushing (10) screwable to the threaded end section (A) and axially movable by the piston, and a gear arrangement (15) for adjusting the nut (4), wherein components of the gear arrangement (15) are a drive element (16) engaging externally on the nut (4) and a drive shaft (17) provided with an engagement structure (18) for a drive tool. The axis of rotation (L1) of the drive shaft (17) is arranged at an angle of preferably 90° to the longitudinal center axis (L) of the piston (7).