Summary of Invention:
The Present innovation generally relates to seat frame & more especially to the low cost, lower mass
tubular component of back frame structure such as for automotive application.
In recent years, vehicle seat design has become very important vehicle marketing feature. Light weight
seats have long been desired in many different types of vehicle, particularly automobile. Lightweight
characteristic not only reduces the cost of seating but also improves the mileage of vehicle. Also a
satisfactory vehicle must be able to withstand not only the normal load associated with a seated
individual, but the load to which the seat is involved in safety & crash situation. The seat frame of this
invention make optimal use of structural material in reacting seat load & also take into account of
manufacturing & process also.
To tilt a seat back a reclining device is provided at the side of connecting portion between seat back &
Cushion frame. The reclining device is available in two types: a double reclining system in which the
reclining device is provided on both side of seat & in single side reclining system in which reclining
device is provided on single side of the seat. This invention is mainly for single side reclining system.
Conventionally, as such Seat back frame utilize a rigid tubular structure to support the load of seated
individual & loads related to crash situation. Traditionally designed seat frame has different types of
tube used for seat frame assembly. Specifications & material thickness for tube also vary in accordance
with testing requirement & vehicle standard. Operations such as swaging, squeezing, flaring etc. are
used, for joining the tube end. These operations not only increased the cycle time but also increased the
overall cost of tubular components.
In addition, in some cases upper tube & lower tube are separately joined to form a tubular component,
which also increased no. of parts & weight of the tube. In case of single continues tube one end of tube
joined with other end by squeezing or notching operation. Controlling the Accuracy of tubular
component with seat back frame is one of the major challenges for the seat manufacturers.
In order to accomplish the aforesaid invention and other objects related to it, an improved design
tubular component used in back frame, which not only reduce the overall cost of frame but also reduce
the manufacturing cost related to the frame. To accomplish the object, the present seat back frame
includes an improved design single tubular component in which both ends of tube are not connected
with each other; however ends are joined with side reclining bracket. As said before tube ends are not
connected with each other, which results in saving of manufacturing cost by eliminating the need of
tube end joining operations. Also in reclining bracket area, a portion of tube is removed which is In
accordance with reduction of weight & material consumption of tube. Tube design is also useful in
improving the overall accuracy of frame & eliminating the need of frame rework. The design of tube also
prohibited the use of grease as both ends are not creating a closed loop.
However the main aim of this invention to replace the traditionally known seat back frames by frames
based on improved designed tubular component.
Drawback in the existing state of art
Conventionally, metal tubes are joined by forming operations like swaging, squeezing, flaring etc. Later
welding is also required on joining area. These operations, however, require several successive
operations performed at different Work stations, which complicates manufacture and necessitates
transfers from one Workstation to the next. This also creates a large amount of Waste in the raw
materials used, and in the tube and sheet metal offcuts.
Other problem solved by invention is to reduce the number of components, in some conventional
designed frame two different tubes are joined together. One tube is known as upper tube & other is
lower tube. Tube manufacturing operations are also different for both the cases.
Moreover in some of the traditionally designed frame, weight of the component is comparatively more;
the reason for this is at tube joining area some portion of one tube merges inside other tube which
increases the weight of tubular component.
Other problem with existing designs is to pour grease in tube; function of grease is to reduce noise of
weld spatter. Adding grease in tube can add significant cost, as it required special purpose machines &
manpower to do this operation. Existing designed tube formed a closed loop which usually generates
difficulty for operator to remove the welding spatter, even in some designs a punching hole is provided
at lower portion of tube but again it could not serve the desired purpose. This is a major limitation in
design of closed loop tube.
in traditionally designed frames, which have single side recliner in that case tube is also provided at area
where recliner bracket is used. Presence of tube in recliner bracket area results in addition of tubular
component weight, which ultimately increase the frame weight.
However, existing designed tubes also required forming operation to maintain the spring back effect.
Controlling the dimension at hinge area may require special quality control parameters to meet the
desired level of accuracy. Thus requirement of higher quality demand increases the cycle time &
manufacturing cost.
Problem(s) or difficulties which the Invention overcomes
The aim of the invention described herein is to solve above mentioned problems, and more particularly
to replace the traditionally known seat back frames by frames based on improved designed tubular
components, bringing reductions in Weight, cost and in the number of parts and facilitating integration
of the various functions that might be desired.
With these objectives in mind the main focus of this invention is to produce a one-piece continues
tubular component, which leads to reduction in number of component with improved manufacturing
feasibility & component cost.
As it will be more clearly understood later, such a structure is particularly easy to produce, since it is
formed from a single part and can provide for significant weight savings without sacrificing the
mechanical strength, particularly at the location of the tube attaching with side bracket component.
The aim of this invention is to solve the above mentioned problem by designing a tube whose ends are
not joining with each other. Both the ends are mating with recliner bracket & connected with it by
welding operation.
This improvement in design also eliminate the need of tube end joining operations such as swaging,
squeezing & flaring as mentioned above in problem statements. Saving in manufacturing cost, process
cost & material cost is the prime goal of this invention.
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Also eliminating the need of tubular components in recliner bracket area is one of the weights saving
approach we have used in this improved design.
Accuracy of the tubular components in joining area was one of the major concerns in existing designs;
here it is designed to solve the problem of accuracy at hinge area. Because tube-is joining at recliner
bracket area but not at hinge area.

1. The seat frame of this invention makes optimal use of structural material in reacting seat load &
also take into account of manufacturing & process also.
2. This not only reduces the overall cost of frame but also reduce the manufacturing cost related to
the frame by eliminating the need of tube end joining operations.
3. Tube design is also useful in improving the overall accuracy of frame & eliminating the need of
frame rework; ^ " v
4. The design of tube also prohibits the use of grease as both ends are not creating a closed loop
thereby saving significant cost.
5. The invented structure is particularly easy to produce, since it is formed from a single part and
can provide for significant weight savings without sacrificing the mechanical strength,
particularly at the location of the tube attaching with side bracket component.
6. This improvement in design also eliminates the need of tube end joining operations such as
swaging, squeezing & flaring etc.
7. It is designed to solve the problem of accuracy at hinge area* Because tube is joining at recliner
bracket area but not at hinge area.
8. In this Invention tubes ends are not connected with each other, which do not form a closed
loop. Hence, if welding spatter is entered in tube, it becomes easier to remove weld as tubes
ends are not joined with each other.