Hammer Drill Handle Vibration Damping via Segmented Guide
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hammer drill designs suffer from vibration transfer to the operator's hands due to inadequate vibration dampening mechanisms, leading to potential hand injury and increased complexity and cost from unnecessary movement coordination within the housing.
Innovation Solution
A vibration dampening mechanism using two distinct points of contact between the handle and the body, with a tubular guide and a resilient cushion, that adjusts to increase support against bending forces as pressure is applied, ensuring minimal sideways movement and efficient vibration absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a movement co-ordination mechanism is provided within the housing to ensure unison movement of handle ends, then the handle movement is coordinated, but the housing space is consumed and device complexity increases
Solution Approach 1:
The movement co-ordination function is extracted from the housing and transferred to the handle itself. The guide mounted on the handle provides the co-ordination mechanism, removing the need for corresponding mechanisms in the housing and freeing up housing space while maintaining handle movement coordination.
Solution Approach 2:
Instead of mounting guides on the housing and having bars slide within them, the invention inverts the arrangement by mounting the guide on the handle and having bars slide within the guide. This reversal transfers the co-ordination mechanism from the housing to the handle, reducing housing space requirements.
2Ease of operation
If guides make contact along the whole length of bars to ensure smooth sliding, then sliding is smooth, but manufacturing tolerances require reduced bar dimensions allowing sideways movement
Solution Approach 1:
The contact between the bar and guide is segmented into discrete points rather than continuous contact along the entire length. Two distinct contact points provide sufficient support against bending forces while eliminating the need for continuous contact, thereby maintaining manufacturing tolerances and preventing sideways movement.
Solution Approach 2:
Instead of providing contact along the whole length of the bar (excessive action), contact is provided at two specific points (partial action). This partial contact is sufficient to support the bar against bending forces and prevent sideways movement, while being easier to manufacture and maintain precision.
3Strength
If constant contact support is provided along the bar length, then support against bending force is constant, but the amount of contact is excessive and increases complexity
Solution Approach 1:
The support mechanism is segmented from continuous contact into two distinct contact points. This segmentation maintains the necessary support against bending forces while simplifying the overall mechanism and reducing the amount of contact required, thereby reducing complexity.
Solution Approach 2:
Instead of providing constant contact support along the entire bar length (excessive action), support is provided at two specific points (partial action). This partial support is sufficient to maintain strength against bending forces while reducing device complexity and the amount of contact required.
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 mechanism effectively reduces vibration transfer to the handle, enhancing operator comfort and reducing the risk of hand injury while maintaining structural integrity and cost-effectiveness by optimizing the contact points and using a helical spring for damping.
Implementation Method 1
a resilient cushion, which biases the handle away from the body and which acts to dampen vibration
Implementation Method 2
a resilient cushion
Implementation Method 3
the resilient cushion... acts to dampen vibration... A first rigid plastic tubular insert... A second rigid plastic tubular insert
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A hammer drill comprising: a body 2 in which is mounted a motor 48 and a hammer mechanism 46 which is driven by the motor 48 when the motor 48 is activated; a tool holder 8 mounted on the front of the body 2 and which is capable of holding a cutting tool 12, the hammer mechanism 46, when driven by the motor 48, capable of imparting impacts to the cutting tool 12, when held by the tool holder 8; a rear handle 4, moveably mounted on to the rear of the body 2 via at least one movement control mechanism and which is capable of moving towards or away from the body 2; a biasing mechanism 104 which biases the rear handle 4 away from the body 2; wherein each movement control mechanism comprises: a first mount; a rod 106, having a longitudinal axis 107, rigidly connected at one of it ends to the first mount; a second mount which slidingly engages with the rod 106 at two distinct points only along its length to allow the rod 106 to slide relative to the second mount in a direction parallel to the longitudinal axis 107 whilst preventing the rod 106 from moving relative to second mount in a direction perpendicular to longitudinal axis 107; wherein one mount 70, 133, 136 is attached to the body 2 and the other mount 92 is attached to the rear handle 4.