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Utveckling av positioneringsled till punktutsug

Friberg, Björn and Persson, Daniel (2003)
Product Development
Abstract
AB Ph. Nederman manufactures capture at source extractors that remove dust and fumes
from a specific area. These extractors are made of a positioning joint which has the
purpose to hold up the extractors’ hood. Presently this joint is made of a double ball joint;
this doesn’t however work in a satisfying way. First and foremost it is hard to move the
joint when repositioning the hood; this is not desirable considering that the hood at any
time has to be able to be repositioned by one hand. The purpose with this thesis is to
improve and generate a new improved positioning joint for a capture at source extractor.
The joint ought to be less costly then the present joint, unless it has considerable
advantages from a technical point of... (More)
AB Ph. Nederman manufactures capture at source extractors that remove dust and fumes
from a specific area. These extractors are made of a positioning joint which has the
purpose to hold up the extractors’ hood. Presently this joint is made of a double ball joint;
this doesn’t however work in a satisfying way. First and foremost it is hard to move the
joint when repositioning the hood; this is not desirable considering that the hood at any
time has to be able to be repositioned by one hand. The purpose with this thesis is to
improve and generate a new improved positioning joint for a capture at source extractor.
The joint ought to be less costly then the present joint, unless it has considerable
advantages from a technical point of view.
This project has followed a structured step by step –method. This method has made it
easier to have control over for example; concept generation, concept selection and detail
design.
A number of solutions were generated and to make it easier to carry through the first
selection (preliminary sorting) these suggestions were divided in to concept groups.
After the preliminary sorting, further development was made to the remaining
suggestions and a final evaluation was made. Three suggestions moved on, one primary
and two backup suggestions. The primary suggestion was named Single ball.
Single ball is a construction of a ball joint, and as the name indicates, it consists of only
one ball. To be able to obtain a semispherical interval movement, a moveable component
is part of the construction, this component is named dome. The dome allows the ball and
the centre of movement to relocate outside the housing that keeps together the joint. This
is why the semispherical interval can be accomplished with only one ball.
A concept of locking, which is disconnected when the joint is to be repositioned, was
developed and joined the primary suggestion after the final evaluation. The concept of
locking has the purpose to fixate the joint by pressuring a pad, coated with high friction
material, against the ball. The pressure against the pad originates from a spring, which is
tightened at the mounting of the joint. When the locking is detached a pulling force is
applied to the friction pad to counteract the spring force and there by the joint will be
released.
In order to test the construction a prototype was made. However, economical factors
limited the manufacturing of the joint, and the exact measurements of the original
drawings could not be used. Instead the prototype was made to obtain the function areas
of the joint. Following testing showed that the joint works, but there are however some
problems to considerate. One of the problems with the joint is that the locking doesn’t
fixate the joint positions in the appointed movement interval. One additional problem is,
that the tongues that the dome consist of, disfigures when load is applied according to
calculations.
To finalize the thesis within reasonable time recommendations were given regarding the
problems that occurred during prototype testing. Suggestions were made to coat more
surfaces with high friction material and to combine the sensitive dome with the house in
order to stiffen the part. (Less)
Please use this url to cite or link to this publication:
author
Friberg, Björn and Persson, Daniel
supervisor
organization
year
type
H2 - Master's Degree (Two Years)
subject
language
Swedish
id
1510981
date added to LUP
2009-12-04 09:32:01
date last changed
2010-02-01 14:40:06
@misc{1510981,
  abstract     = {AB Ph. Nederman manufactures capture at source extractors that remove dust and fumes
from a specific area. These extractors are made of a positioning joint which has the
purpose to hold up the extractors’ hood. Presently this joint is made of a double ball joint;
this doesn’t however work in a satisfying way. First and foremost it is hard to move the
joint when repositioning the hood; this is not desirable considering that the hood at any
time has to be able to be repositioned by one hand. The purpose with this thesis is to
improve and generate a new improved positioning joint for a capture at source extractor.
The joint ought to be less costly then the present joint, unless it has considerable
advantages from a technical point of view.
This project has followed a structured step by step –method. This method has made it
easier to have control over for example; concept generation, concept selection and detail
design.
A number of solutions were generated and to make it easier to carry through the first
selection (preliminary sorting) these suggestions were divided in to concept groups.
After the preliminary sorting, further development was made to the remaining
suggestions and a final evaluation was made. Three suggestions moved on, one primary
and two backup suggestions. The primary suggestion was named Single ball.
Single ball is a construction of a ball joint, and as the name indicates, it consists of only
one ball. To be able to obtain a semispherical interval movement, a moveable component
is part of the construction, this component is named dome. The dome allows the ball and
the centre of movement to relocate outside the housing that keeps together the joint. This
is why the semispherical interval can be accomplished with only one ball.
A concept of locking, which is disconnected when the joint is to be repositioned, was
developed and joined the primary suggestion after the final evaluation. The concept of
locking has the purpose to fixate the joint by pressuring a pad, coated with high friction
material, against the ball. The pressure against the pad originates from a spring, which is
tightened at the mounting of the joint. When the locking is detached a pulling force is
applied to the friction pad to counteract the spring force and there by the joint will be
released.
In order to test the construction a prototype was made. However, economical factors
limited the manufacturing of the joint, and the exact measurements of the original
drawings could not be used. Instead the prototype was made to obtain the function areas
of the joint. Following testing showed that the joint works, but there are however some
problems to considerate. One of the problems with the joint is that the locking doesn’t
fixate the joint positions in the appointed movement interval. One additional problem is,
that the tongues that the dome consist of, disfigures when load is applied according to
calculations.
To finalize the thesis within reasonable time recommendations were given regarding the
problems that occurred during prototype testing. Suggestions were made to coat more
surfaces with high friction material and to combine the sensitive dome with the house in
order to stiffen the part.},
  author       = {Friberg, Björn and Persson, Daniel},
  language     = {swe},
  note         = {Student Paper},
  title        = {Utveckling av positioneringsled till punktutsug},
  year         = {2003},
}