International Journal of Mechanical Engineering and Technology (IJMET)
Volume 7, Issue 2, March-April 2016, pp. 261–265, Article ID: IJMET_07_02_027
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ISSN Print: 0976-6340 and ISSN Online: 0976-6359
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MECHANICALLY OPERATED
WHEELCHAIR CONVERTIBLE
STRETCHER
Ninad M. Borkar
Department of Mechanical Engineering,
Dr. Babasaheb Ambedkar College of Engineering and Research,
Nagpur, Maharashtra. India
Saurabh A. Apte
Department of Mechanical Engineering,
Dr. Babasaheb Ambedkar College of Engineering and Research,
Nagpur, Maharashtra. India
Tejas N. Deshmukh
Department of Mechanical Engineering,
Dr.Babasaheb Ambedkar College of Engineering and Research,
Nagpur, Maharashtra. India
Sampada M. Apte
Lecturer at Department of Computer Engineering,
Dharampeth Polytechnic, Nagpur, Maharashtra. India
ABSTRACT
The problem of transferring the patients exists from ancient times. People
who get seriously injured or ill were carried by others by means of wooden
stretcher with cloth or leather tied to it. Afterwards they were carried on
wheels which reduced the effort of the people carrying the patients. Alhough
we have evolved in the field of healthcare and technology we are not yet able
to address this problem efficiently.
Mobility aids are used for transportation of patients. Wheelchairs and
stretchers are the most commonly used mobility aids for the movement of
patients. Transferring the patients from wheelchair to stretcher or to the
medical bed or vice versa is always an issue for the attendant or nurse. There
is a revolution of wheelchairs available today driven by needs and desire of
man.
Hence we propose a design of wheelchair convertible stretcher which is a
boon to the medical field. It is so made that it could be maintained and
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Ninad M. Borkar, Saurabh A. Apte, Tejas N. Deshmukh and Sampada M. Apte
operated easily either by the patient or by the attendant according to the
comfort of the patient.
Cite this Article Ninad M. Borkar, Saurabh A. Apte, Tejas N. Deshmukh and
Sampada M. Apte, Mechanically Operated Wheelchair Convertible Stretcher.
International Journal of Mechanical Engineering and Technology, 7(2), 2016,
pp. 261–265.
http://iaeme.com/Home/issue/IJMET?Volume=7&Issue=2
1. INTRODUCTION
In simple words a wheelchair can be described as a structure having a set of wheels
attached to a chair. Wheelchair is a device which can empower and enable a person
with a disability to live a normal and independent life. Over the years wheelchairs
have evolved rapidly from the manual wheelchairs to the powered wheelchairs. But
still these wheelchairs have not been able to satisfy the needs of the disabled people. It
is therefore critical that the problems of disabled be understood and accordingly
wheelchairs are developed fulfilling their needs. So we have designed a multipurpose
wheelchair that can work as wheelchair as well as a Stretcher. Its construction is so
easy and can be operated and maintained easily. We have used simple mechanical
linkages along with seat back recliner mechanism to achieve the required motion.
This paper is the result of a design and development of a multi functional Wheelchair
that would perform all the required functions.
Objectives of the study
•
•
•
Decrease the cost by using new mechanism.
Works reliably under different operating conditions.
To save space and precluding exertion of the patient.
2. LITERATURE REVIEW
The author in [1] gives us various concepts regarding wheelchair convertible
stretcher. Concept 1 enlightens us about a sliding tubular frame which is attached to
the back rest of the wheelchair. A handle is provided in the back rest so that the user
can pull it easily and can convert it into stretcher. Concept 3 gives us an insight to the
hydraulic scissor lifter mechanism, so that the height can be adjusted according to the
user’s convenience. A hydraulic scissor lifter mechanism lifts the entire wheelchair
into stretcher. Concept 5 is based on the gear mechanism. According to the rotation of
the middle wheel, the front and back seats are rotated in opposite direction and
stretcher arrangement is achieved. The author in [4] uses pneumatic power for the
operation of the wheelchair convertible stretcher although the air supply is some
distance away from the product.
3. CONSTRUCTION
The wheelchair convertible stretcher consists of following components:1. Backrest: Backrest of wheelchair convertible stretcher is made up of square crosssection (1” X 1”) and flat mild steel plates are welded in it. It is attached to the base
with hinges and seat back recliner mechanism.
2. Seat: The seat is made up of mild steel of square cross-section (1” X 1”) and flat mild
steel plates are welded in the frame. It is directly connected to the base of the
wheelchair convertible stretcher.
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Mechanically Operated Wheelchair Convertible Stretcher
3. Leg rest: Leg rest of wheelchair convertible stretcher is also made up of mild steel
square cross-section (1” X 1”) and flat mild steel plates are welded in the frame. It is
attached to the seat (base) by means of hinges.
4. Foot rest: The footrest is made of the mild steel square cross-section by bending its
edges and is welded at the bottom of the leg rest.
5. Seat back recliner mechanism: The seat back recliner mechanism is rigidly attached
to the seat and backrest by means of nuts and bolts. This mechanism helps in locking
of backrest and leg rest at some specific angles. Fig. A and Fig. B shows the initial
and final position of seat back recliner mechanism respectively.
Fig. A
Fig. B
6. Mechanical linkages: There are three linkages out of which two are welded at the
backrest and leg rest respectively. The third link is used to connect the two links. The
welded links at the backrest and leg rest are at an angle of 30° and 62.5° respectively.
7. Hinges: These are the most important part of wheelchair convertible stretcher. It is
connected in between backrest and seat (base) and in between seat (base) and leg rest.
It is connected in order to convert wheelchair into stretcher and vice versa.
8. Fasteners: These are used to connect the linkages and to fix the seat back recliner
mechanism rigidly which helps in the process of conversion of wheelchair into
stretcher and vice versa.
9. Caster wheels: The caster wheels are used are used for smooth travelling of
wheelchair convertible stretcher and are attached at the bottom of the base of
wheelchair convertible stretcher. The height of caster wheels is 4”.
4. WORKING
The working of wheelchair convertible stretcher is so simple that the patient feels
comfortable during the transformation from wheelchair into stretcher and vice versa.
In operation when the wheelchair is to be converted into stretcher the operation
starts with pulling the lever. The lever is connected to the backrest with radial spring.
After pulling the lever, the gear in the seat back recliner mechanism un-meshes
and due to the weight on the backrest it will gradually lower down. This will convert
the wheelchair into the stretcher.
Now if we have to convert the stretcher into wheelchair, again pull the lever of the
seat back recliner mechanism. By applying light load on the leg rest, the backrest will
also rise up till its original position.
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Ninad M. Borkar, Saurabh A. Apte, Tejas N. Deshmukh and Sampada M. Apte
The advantage of using this mechanism is that during conversion of wheelchair
into stretcher the backrest can be locked at any angle according to the need and
comfort of patient.
5. DESIGN CALCULATIONS
Dimensions of wheelchair convertible stretcher are as follows:PART NAME
LENGTH
WIDTH
THICKNESS
BACKREST
28”
22”
1”
SEAT
19”
22”
1”
LEGREST
23”
22”
1”
FOOTREST
6”
22”
1”
For the above mentioned dimensions of the wheelchair convertible into stretcher the
length of links used are Link a = 21”
Link b = 15.2”
Link c = 16.9”
Fig. C shows the links at two extreme positions.
6. CONCLUSION
Fig. C
Our study was intended to develop a concept of wheelchair convertible stretcher with
the motivation of saving space and prevent exertion of patient as well as by making
sure that the patient does not get hurt.
The mechanism and safety of patient were our main priorities while designing the
conceptual model of wheelchair convertible stretcher.
Our study shows that it is possible to save 50% space by using wheelchair
convertible stretcher rather than using wheelchair and stretcher separately.
This design eliminates the steps of shifting patients from wheelchair to stretcher
and vice versa as nurturing of disabled people becomes difficult. Our design will thus
be an efficient mobility aid for the medical field.
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Mechanically Operated Wheelchair Convertible Stretcher
REFERENCES
[1]
[2]
[3]
[4]
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[6]
[7]
Sreerag C S, Gopinath C, Manas Ranjan Mishra, “Design and Development of
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Mr. Amos Winter, “Mechanical principle of wheelchair design”, Graduate
Student, Department of Mechanical Engineering, Massachusetts Institute of
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Jingtao.Chen, Bing.Teng, Yali.Yang, “Design of the Wheelchair Bed”, Rev. Téc.
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Prof. Abhinav v. Deshpande, A Low-Cost Electric Power Wheelchair With
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Development of Wheelchair for People Disabled in Legs”, International Journal
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