Shock absorbing type steering column assembly

A shock absorbing type steering column assembly includes a first bracket fixed to a steering column at a middle portion thereof, a second bracket formed integrally with the car body for supporting the first bracket, and a connecting device having an energy absorbing member for supporting the first bracket until a predetermined load is applied upon a secondary collision and absorbing a collision energy applied on the steering column and allowing the first bracket to move relative to the second bracket to absorb the shock energy when the predetermined load is applied on the steering column upon a secondary collision. The energy absorbing member includes a metallic wire which has a basic portion and elongated deformable portions extending respectively from the ends of said basic portion toward free ends. Each of the deformable portions has a folded-back portion and a deformable portion extending from the folded-back portion to the free end. The energy absorbing member is retained at the basic portion by one of the first and the second brackets and engaged or engageable with the other of the first and second brackets at the folded-back portion. When the applied load exceeds the predetermined value and the first bracket moves forward relative to the second bracket, the wire is so urged by the first bracket that the folded-back portions are shifted along the deformable portions toward the free ends, thereby absorbing the collision energy.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a shock absorbing type steering column 
assembly for preventing the body of a driver from receiving a large impact 
at the time of a secondary collision by displacing the steering wheel 
forward. 
2. Description of the Prior Art 
Upon an automobile collision, subsequent to a so-called primary clash in 
which the automobile collides with another automobile, a so-called 
secondary collision in which the driver collides with the steering wheel 
occurs. In order to minimize the impact on the driver at this secondary 
collision to protect the driver's life, it is conventionally arranged to 
use a so-called collapsible steering shaft which is entirely contracted 
when a strong impact is given and which has a steering wheel fixed to one 
end thereof, and to employ an impact absorbing type of a steering column 
through which said steering shaft is passed. 
As a shock absorbing type steering column apparatus to be used for such 
purpose, there is conventionally known, for example, one disclosed in 
Japanese Utility Model Laid-Open No. 5-75057. This conventionally-known 
steering column apparatus of a shock or impact absorbing type is 
structured as shown in FIGS. 19 to 21 of the accompanying drawings. 
Referring to FIGS. 19 to 21, a steering column 1 is structured by 
combining, for example, an outer column with an inner column in a 
telescopic manner, and when a strong force is applied along the direction 
of the shaft (the lateral direction in FIG. 19, and the direction 
perpendicular to the sheet surface in FIG. 20), the entire column is 
contracted. Inside such steering column 1, the steering shaft 2 is 
supported as only being free to rotate. A steering wheel is fixed to the 
rear end portion of the steering shaft 2, at the portion protruding from 
the opening at the rear end of the steering column 1. 
A supporting bracket 3 for supporting the above-mentioned steering column 1 
on the car body 30 has a pair of supporting plates 4a, 4b arranged 
laterally. Then, both supporting plates 4a, 4b laterally sandwich 
therebetween a raising/lowering bracket 5 which serves as a support 
bracket and is fixed by welding to the lower surface of the middle portion 
of said steering column 1 along the width direction (the direction 
perpendicular to the sheet surface in FIG. 19, and the lateral direction 
in FIG. 20) of this steering column 1. On both of the right and left side 
walls of this raising/lowering bracket 5, cut-away portions 6a, 6b are 
formed as being open on side of the rear end edge thereof (the right end 
edge in FIG. 19). Also, vertically elongated holes 7a, 7b which serve as 
through-holes are respectively formed in portions of said supporting 
plates 4a, 4b which are aligned with these cut-away portions. A tilt 
adjusting nut 9 is threadably engaged with the tip end of a tilt adjusting 
bolt 8 serving as a rod-like connecting member which is passed through 
from one to the other of these elongated holes 7a, 7b and cut-away 
portions 6a, 6b (from right to left in FIG. 20). This tilt adjusting bolt 
8 is arranged to raise and lower along the elongated holes 7a, 7b but is 
incapable of rotating due to the engagement of a head portion 10 with a 
side edge of elongated hole 7b. 
A gap between the tilt adjusting nut 9 and the head portion 10 can be 
changed by rotating the tilt adjusting nut 9 by use of an unrepresented 
tilt adjusting lever. Then, by changing this gap, it is possible to fix 
the raising/lowering bracket 5 to the supporting bracket 3 an thereby fix 
the steering column 1, or to release such fixation of the bracket 5 in 
order to adjust a vertical position of the steering column 1. 
Further, on a portion which exists in the middle portion of the tilt 
adjusting bolt 8 and the inner side of the raising/lowering bracket 5, the 
rear end portion of an energy absorbing member 11 (the right end portion 
in FIGS. 19 and 21; the front and rear sides are defined in terms of the 
moving direction of the automobile) is externally fitted and supported. 
Then, the front end portion of this energy absorbing member 11 (the left 
end portion in FIGS. 19 and 21) is fixed by welding to the lower surface 
of the middle portion of the steering column 1. Therefore, the rear end 
portion of the energy absorbing member 11 is supported on the car body 30 
which is not displaced even at the secondary collision, through the tilt 
adjusting bolt 8 and the supporting bracket 3, while the front end portion 
of said energy absorbing member is supported by the steering column 1 
which is displaced forward at the secondary collision. 
This energy absorbing member 11 is formed to be corrugated, as shown in 
FIG. 21, by stamping out from one metallic plate having elasticity. Also, 
a pair of folded-back portions 13a, 13b are laterally provided and 
attached to a supporting portion 12 which is provided at the rear end 
portion of this energy absorbing member 11, and round holes 114a, 114b for 
inserting said tilt bolt 8 therethrough are formed in the respective 
folded-back portions 13a, 13b. Further, a tongue piece 15 is formed in the 
front end portion of the energy absorbing member 11, and this tongue piece 
15 can be fixed to the lower surface of said steering column 1 by welding. 
The conventional steering column apparatus of a shock or impact absorbing 
type, which is constituted by inserting the energy absorbing member 11 
having a configuration as mentioned above between the tilt adjusting bolt 
8 and the steering column 1, as shown in FIGS. 19 and 20, is operated as 
follows. When an impact force for pushing said steering column 1 forward 
is given by the secondary collision caused by an accidental collision, the 
energy absorbing member 11 allows said steering column 1 to be displaced 
forward, while being plastically deformed to be elongated in the 
longitudinal direction. The impact energy which is propagated from the 
steering wheel to the steering column 1 is absorbed because of the plastic 
deformation of the energy absorbing member 11. For this reason, the impact 
force to be applied on the body of the driver at the time of the secondary 
collision is mitigated so as to protect the driver. 
In the conventional structure shown in FIGS. 19 to 21, there arises no 
special problem in terms of protection of the driver at the time of the 
secondary collision. However, a manufacturing cost of the energy absorbing 
member 11 is increased for the reason (1) described below, and moreover, 
an assembling process of this energy absorbing member 11 becomes 
complicated for the following reasons (2) and (3). 
(1) The complicated configuration of the energy absorbing member 11 brings 
about a high manufacturing cost of the press die. Moreover, when this 
energy absorbing member 11 is stamped out from a steel plate, much scrap 
material is left, to degrade a yield on the material. 
(2) It is necessary to insert at the assembling the tilt adjusting bolt 8 
serving as a connecting member through the pair of cut-away portions 6a, 
6b, elongated holes 7a, 7b, and round holes 114a, 114b, respectively. 
Because of this inserting process, a process for aligning the round holes 
114a, 114b provided on the energy absorbing member 11 with said cut-away 
portions 6a, 6b and said elongated holes 7a, 7b becomes complicated. 
(3) A welding process for connecting the tongue piece 15 at the front end 
of the energy absorbing member 11 with the lower surface of the middle 
portion of the steering column 1 becomes necessary. If such a welding 
process is conducted when the steering column apparatus of an impact 
absorbing type is assembled, the assembling process becomes complicated. 
Because of the cost increase of the energy absorbing member owing to the 
above-mentioned reason (1) and a degraded efficiency of the assembling 
process owing to the above-mentioned reasons (2) and (3), the entire cost 
of the steering column apparatus of the impact absorbing type which is 
disclosed in Japanese Utility Model Laid-Open No. 5-75057 is increased. 
As a steering column apparatus of a shock absorbing type, apart from that 
mentioned above, there are ones disclosed in Japanese Utility Model 
Laid-Open No. 6-16851, for example, and the like. However, these steering 
column apparatuses have the same problems as mentioned above. 
SUMMARY OF THE INVENTION 
A steering column apparatus of the shock absorbing type of the present 
invention has been devised taking such circumstances into consideration. 
Like a steering column apparatus of a shock absorbing type as 
conventionally known, a steering column assembly of the shock absorbing 
type of the present invention may comprise: a supported bracket which is 
fixed to a middle portion of a steering column along the width direction 
of this steering column, a supporting bracket having a pair of supporting 
plates for sandwiching the supported bracket therebetween and supported by 
and fixed to the vehicle body for supporting the supported bracket; a 
cut-away portion formed as being open on the side of the rear end edge of 
this supported bracket in a portion of the supporting bracket opposite to 
each of the supporting plates; a through-hole formed in each of the 
supporting plates; a rod-like connecting member for connecting and 
supporting the supported bracket to the supporting bracket in a state in 
which the connecting member is passed through each of these cut-away 
portions and through-holes, and an energy absorbing member provided 
between the supporting bracket and the steering column. 
Especially, in the steering column assembly of the shock absorbing type 
according to an embodiment of the present invention, the energy absorbing 
member is formed by bending a metallic wire and is provided with a basic 
portion and two deformable portions which are integrally connected to this 
basic portion. Then, the basic portion is connected to and supported by a 
portion which is a part of the supported bracket and positioned in front 
of said connecting member. Also, the deformable portions each has 
folded-back portion which is formed in a middle portion thereof around the 
rear face side of the connecting member. The folded-back portions are 
folded back at the rear side of this connecting member. 
Further, if needed, the whole or a part of the metallic wire which 
constitutes the energy absorbing member is made to have elasticity and to 
be latched at a part of the supporting bracket as being detachable upon 
the secondary collision. Then, the energy absorbing member is arranged to 
be provided between said supporting bracket and the connecting member, so 
as to elastically support the weight of the steering column. 
The steering column assembly according to an embodiment of the present 
invention constituted as described above is operated in the following 
manner. Upon the secondary collision, a forward load is given with impact 
to the steering column from the steering wheel through the steering shaft. 
Then, this load displaces the whole or a part of the steering column 
forward. On the other hand, the supporting bracket and the connecting 
member are not displaced and remain to be supported on the car body. 
Therefore, said connecting member is displaced backward with respect to 
the steering column upon the displacement of the steering column (in 
reality, the connecting member does not move, but the steering column is 
displaced forward). At the same time, the basic portion of the energy 
absorbing member is pulled forward by said steering column. 
As described above, when the basic portion of the energy absorbing member 
is pulled forward, the folded-back portions which are formed on the 
deformable portions of this energy absorbing member are shifted by or 
drawn against said connecting member so that this energy absorbing member 
is deformed. That is, upon the forward displacement of said steering 
column, said folded-back portions are shifted from the parts in which they 
are originally provided toward the tip ends of the deformable portions. 
Thus, by deforming said energy absorbing member to shift the folded-back 
portions toward the tip ends of the deformable portions, it is possible to 
absorb the shock or impact energy which is applied to the steering wheel 
from the body of the driver upon the secondary collision. As a result, the 
impact to be applied on the body of the driver is mitigated so as to 
protect of the driver. 
The operation described above is similar to that of a steering column 
apparatus of a shock absorbing type according to the prior invention 
disclosed in Japanese Patent Application No. 7-102567. Especially, in the 
case of the shock absorbing type steering column apparatus according to 
one embodiment of the present invention, since the energy absorbing member 
is formed by bending a metallic wire and the basic portion of this energy 
absorbing member is connected to and supported by the supported bracket, 
the welding process for assembling this energy absorbing member at a 
predetermined portion becomes no longer necessary. 
Moreover, when the assembly is arranged to elastically support the weight 
of the steering column by the elasticity of the energy absorbing member, 
if need be, it is no longer necessary to separately provide a spring for 
supporting the weight of the steering wheel at the time of a tilt 
adjusting process for adjusting the height of the steering wheel. That is, 
when the supporting force for the supported bracket with respect to the 
supporting bracket for the tilt adjusting process is lost, the steering 
column drops to the lower limit position for the adjustment if such 
condition continues. Since the tilt adjusting process is difficult to 
carry out in such state, a balancing spring is provided between the 
portion fixed to the car body and the portion fixed to the steering column 
in a conventional apparatus, so as to support the weight of this steering 
column. In the case of the steering column assembly of the shock absorbing 
type of the present invention, since a metallic wire is used for the 
energy absorbing member, it is possible to support the weight of the 
steering column with this energy absorbing member so as to leave such 
balancing spring out and to reduce the cost further, if needed.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In all of the embodiments described below, the components denoted by same 
reference numerals and symbols have the same or similar structures and 
functions. 
FIGS. 1 to 3 show the first embodiment of the present invention. A steering 
column 1 is, when a forward strong impact load is given through a steering 
wheel and a steering shaft 2 upon a secondary collision, arranged to be 
freely displaced forward. Note that such structure is conventionally known 
and not the point of the present invention so that illustration and 
detailed description thereof will be omitted. In a middle portion of such 
steering column 1, a raising/lowering bracket 15 which functions as a 
supported bracket is fixed by welding along the width direction (the 
perpendicular direction to the sheet plane in FIG. 1, and the lateral 
direction in FIG. 2) of this steering column 1. On the other hand, a 
supporting bracket 13 is firmly fixed to a car body 30 in such a manner 
that the supporting bracket should not be detached from a car body 30 
notwithstanding the above-mentioned impact load. This supporting bracket 
13 has a pair of supporting plates 14a, 14b for sandwiching the 
raising/lowering bracket 15 from the both sides thereof. 
A pair of cut-away portions 16a, 16b are formed laterally in parts of the 
raising/lowering bracket 15 opposite to the supporting plates 14a, 14b, as 
being open on the rear end edge side (the right end edge side in FIG. 1) 
of this raising/lowering bracket 15. Also, slots 17a, 17b elongated in the 
vertical direction which are through-holes are formed on the supporting 
plates 14a, 14b. A tilt adjusting bolt 18 which is a rod-like connecting 
member is passed through these cut-away portions 16a, 16b and elongated 
holes 17a, 17b. At the same time, a tilt adjusting nut 19 is threadably 
engaged with the tip end (the left end portion in FIG. 2) of this tilt 
adjusting bolt 18 so that the raising/lowering bracket 15 is connected to 
and supported by the supporting bracket 13. The tilt adjusting bolt 18 is 
arranged to be passed through the slots 17a, 17b, and is capable of being 
raised and lowered when the tilt adjusting nut 19 is loosened, but is 
incapable of rotating due to engagement of a head portion 10 with a side 
edge of the elongated hole or slot 17b. 
Then, an energy absorbing member 16, which is a feature of the present 
invention, is provided between the supporting bracket 13 and the steering 
column 1. In the illustrated embodiment, this energy absorbing member 16 
is provided between the tilt adjusting bolt 18, which is supported by the 
supporting bracket 13 at both ends thereof so as not to move in the back 
and forth direction (the lateral direction in FIG. 1, and the 
perpendicular direction to the sheet plane in FIG. 2) in spite of an 
impact load at the time of the secondary collision and the 
raising/lowering bracket 15, which is displaced together with the steering 
column 1 forward (to the left in FIG. 1) upon the secondary collision. 
The above-mentioned energy absorbing member 16 which constitutes part of a 
steering column assembly of a shock absorbing type of this embodiment is 
formed in a shape as shown in FIG. 3, by bending a plastically deformable 
metallic wire. This energy absorbing member 16 is provided with a basic 
portion 17 formed at the center thereof and a pair of right and left 
deformable portions 18a, 18b which are integrally connected to or 
integrally extended from this basic portion 17. The basic portion 17 is 
formed in a U-shape by bending at substantially right angles both ends of 
a central linear portion 17x backward. Also, the deformable portions 18a, 
18b are provided with semi-arch folded-back portions 19a, 19b, 
respectively, at middle portions thereof in a direction substantially 
perpendicular to the extending direction of the central linear portion 
17x. As a result, each of the deformable portions is formed in a J-shape 
as a whole. 
In order to mount the energy absorbing member 16 as described above, a 
latching plate 20 is bent upward at the front end (the left end in FIG. 1) 
of the raising/lowering bracket 15. When the steering column of the impact 
absorbing type is assembled, the central linear portion 17x of the 
U-shaped basic portion 17 of said energy absorbing member 16 is latched 
from the inside thereof on the front face side of this latching plate 20. 
The deformable portions 18a, 18b of this energy absorbing member 16 are 
folded back at the rear of the tilt adjusting bolt 18 so that the 
folded-back portions 19a, 19b formed in the midway are provided on the 
periphery of the rear face side of the middle portion of the tilt bolt 18 
(the right face side in FIG. 1). 
The front end of the energy absorbing member 16, that is, the end portions 
opposite to the folded-back portions 19a, 19b of the deformable portions 
18a, 18b may be positioned by some means, but are arranged to be free in 
the form shown. 
The shock absorbing type steering column assembly of the present invention 
structured as described above is operated in the following manner to 
protect the driver in the case of an accidental collision. At the 
secondary collision, a forward load (to the left in FIG. 1) is given to 
the steering column 1 with impact from the steering wheel through the 
steering shaft 2. Then, with this load, in a part or the whole of the 
steering column 1, at least the portion thereof fixed to the 
raising/lowering bracket 15 is displaced forward. On the other hand, the 
supporting bracket 13 and the tilt adjusting bolt 18 remain supported on 
the car body 30 and are not displaced. Therefore, upon start of the 
displacement of the steering column 1, the tilt adjusting bolt 18 is 
displaced backward relatively to the steering column 1 (in reality, the 
tilt adjusting bolt 8 is not moved, but the steering column 1 is displaced 
forward). At the same time, the basic portion 17 of the energy absorbing 
member 16 is pulled forward by the latching plate 20 which is formed in 
the front end portion of the raising/lowering bracket 15. 
When the basic portion 17 of the energy absorbing member 16 is pulled 
forward in this manner, the folded-back portions 19a, 19b which are formed 
in the deformable portions 18a, 18b of this energy absorbing member 16 are 
drawn or pulled against the tilt adjusting bolt 18 and the folded-back 
portions are shifted along the deformable portions, so that this energy 
absorbing member 16 is displaced. That is, upon the forward displacement 
of the steering column 1, the folded-back portions 19a, 19b are moved or 
shifted toward the tip ends of the deformable portions 18a, 18b from the 
portions at which they are originally formed. Since the energy absorbing 
member 16 is deformed in order to move the folded-back portions 19a, 19b 
to the tip ends of these deformable portions 18a, 18b in this manner, the 
shock energy applied on the steering wheel from the body of the driver 
upon said secondary collision is absorbed. As a result, the shock or 
impact applied on the body of the driver is mitigated, so as to protect 
the driver. 
Especially, in the case of the steering column assembly of the shock 
absorbing type of the present invention, since the energy absorbing member 
16 is formed by bending a metallic wire and the basic portion 17 of this 
energy absorbing member 16 is hooked or retained by the raising/lowering 
bracket 15 to be supported, the welding process for assembling the energy 
absorbing member 16 at a predetermined portion is no longer necessary. 
Also, since the energy absorbing member 16 is formed by bending the 
metallic wire, the material is hardly wasted, to improve a yield of the 
material. Also, since no complicated die is required to process the energy 
absorbing member 16, the manufacturing cost can be further reduced in this 
respect. Further, the process for aligning the cut-away portions 16a, 16b 
with the elongated holes 17a, 17b and the folded-back portions 19a, 19b in 
order to pass the tilt adjusting bolt 18 through these components in the 
assembling work can be carried out more easily. Therefore, the assembling 
work can be performed more efficiently. 
Next, FIG. 4 shows another energy absorbing member 216 which has a slightly 
different configuration from that in the first embodiment, as the second 
embodiment of the present invention. In this second embodiment, slant 
portions 221a, 221b are formed between both of end portions of a basic 
portion 217 and a pair of deformable portions 218a, 218b. When the basic 
portion 217 is pulled forward at a secondary collision, these slant 
portions 221a, 221b are first extended and then folded-back portions 219a, 
219b which are provided in the deformable portions 218a, 218b are drawn or 
pulled against the tilt adjusting bolt 18 (see FIGS. 1 and 2). Therefore, 
in this second embodiment, it is possible to reduce the load which is 
generated at the moment when the steering column 1 (FIGS. 1 and 2) starts 
to be displaced forward upon the secondary collision. 
Next, FIGS. 5 to 7 show the third embodiment of the present invention. In 
this third embodiment, description of the same arrangements as those in 
the first embodiment will be omitted. In the third embodiment, an energy 
absorbing member 316 has the same configuration as that in FIG. 3, but is 
assembled upside down. In addition, in the third embodiment, a pair of 
latching cut-away portions 322a, 322b are formed on both right and left 
side edges of the upper end portion of a latching plate 320a which is 
formed on the front end edge (the left end edge in FIG. 5) of a 
raising/lowering bracket 305, and a pair of left and right small round 
holes 323a and 323b are formed beneath these latching cut-away portions 
322a and 322b, respectively. Note that one elongated hole may be formed 
instead of these small round holes 323a, 323b, as in a form like these 
round holes 323a, 323b are made to be continuous. The energy absorbing 
member 316 is assembled into such latching plate 320a in a state that the 
basic portion 317 is latched by both latching cut-away portions 322a, 322b 
and a portion closer to the tip end than the folded-back portions 319a, 
319b (the portion closer to the left sheet end in FIG. 5) is passed 
through the small round holes 323a, 323b in the middle portion of the pair 
of deformable portions 318a, 318b. Note that in the assembled state, the 
forms an d dimensions of the energy absorbing member 316 and the latching 
plate 320a are determined such that a part of the energy absorbing member 
316 is elastically pressed against the peripheries of the latching 
cut-away portions 322a, 322b and the inner peripheries of the small round 
holes 323a, 323b. Therefore, no play is given to the energy absorbing 
member 316 with respect to the latching plate 320a after the assembling, 
and play noise is not generated in the assembled unit. Reference numbers 
306a and 306b designate rearwardly open cut-away portions of the 
raising/lowering bracket 305. 
Also in this third embodiment, with the same operations as in the first 
embodiment described above, the impact energy is absorbed while the 
folded-back portions 319a, 319b of the deformable portions 318a, 318b are 
moved toward the tip ends of these deformable portions 318a, 318b at the 
secondary collision. Especially beneficial, in the case of the third 
embodiment, since a part closer to the tip end than the folded-back 
portions 319a, 319b is made to pass through the above-mentioned small 
round holes 323a, 323b in the middle portions of the deformable portions 
318a, 318b, an amount of winding (angle) of each of said folded-back 
portions 319a, 319b with respect to the middle portion of the tilt 
adjusting bolt 18 can be stably maintained after the commencement of the 
secondary collision. Therefore, the capability of absorbing energy at the 
secondary collision is stabilized. 
Next, FIG. 8 shows the fourth embodiment of the present invention. In this 
fourth embodiment, a sleeve 24 which is made of metal, synthetic resin, or 
the like, in the form of a tube is fitted on the middle portion of the 
tilt adjusting bolt 18 rotatably, and the folded-back portions 319a, 319b 
of the energy absorbing member 316 pass around this sleeve 24. In the case 
of the fourth embodiment arranged as described above, sleeve 24 is rotated 
at the time of secondary collision, whereby the folded-back portions 319a, 
319b are stably drawn against the sleeve or shifted. Other arrangements 
and operations in the fourth embodiment are the same to those in the third 
embodiment described before. 
Next, FIG. 9 shows the fifth embodiment of the present invention. In this 
fifth embodiment, a gap 25 is interposed between the tilt adjusting bolt 
18 and the folded-back portion 319a (319b). At the time of secondary 
collision, the steering column 1 is displaced forward by the length L25 of 
this gap 25 (to the left in FIG. 9), and then the folded-back portion 319a 
(319b) starts to be drawn or pulled against the tilt adjusting bolt 18. 
Since a resistance (the resistance of the static friction between the 
inner side faces of a supporting plate and the outer side faces of 
raising/lowering bracket 305) which is to be overcome when the steering 
column 1 starts to be displaced is comparatively large, no "drawing" or 
"pulling" of the turn-back portion 319a (319b) occurs due to the gap 25 
immediately after the start of displacement of the steering column 1, 
whereby it is more easy to control a load of the steering column assembly 
of the shock absorbing type as a whole. Other arrangements and operations 
in this fifth embodiment are the same as those in the third embodiment 
described before. 
Next, FIG. 10 shows the sixth embodiment of the present invention. In this 
sixth embodiment, a metallic wire for constituting an energy absorbing 
member 616 has elasticity and the tip ends of a pair of deformable 
portions 618a, 618a' (618b, 618b' ) of the energy absorbing member 616 are 
latched by a portion of a supporting bracket 603 as being freely 
detachable upon a secondary collision. That is, elasticity is given to 
each of the deformable portions 618a, 618a' (618b, 618b') in the direction 
in which the tip ends of the deformable portions are displaced downward 
(the direction in which the radius of curvature of each of the folded-back 
portions provided in the deformable portions 618a, 618a' (618b, 618b') is 
decreased). Tip latching portions 626a, 626b which are respectively formed 
by bending the tip ends of the deformable portions are latched by cut-away 
portions 27a, 27b which are formed at the front end edges (the left end 
edge in FIG. 10) of a pair of supporting plates 64a, 64b for constituting 
a supporting bracket 603. The latching portions 626a, 626b are thus 
latched by the cut-away portions 27a, 27b, and the deformable portions 
618a, 618a' (618b, 618b') are provided between these cut-away portions 
27a, 27b and the small round holes 323a, 323b of the latching plate 320a 
of the raising/lowering bracket 605, whereby the pair of right and left 
deformable portions 618a, 618b elastically support the weight of the 
steering column 1. 
If it is so arranged that the weight of the steering column 1 be 
elastically supported by the elasticity of the energy absorbing member 616 
as described above, a spring for supporting the weight of the steering 
column 1 is no longer required separately at the time of the tilt 
adjusting process for adjusting the height of the steering wheel. As a 
result, it is possible to reduce the cost further. 
Incidently, in the case of this sixth embodiment, it is sufficient if the 
tip ends of the deformable portions 618a, 618a'; 618b, 618b' are latched 
as being detachable upon the secondary collision, and they are not always 
required to have such constitutions as shown in FIG. 10. For example, it 
is possible to form a small round hole 29a (29b) in a folded-back portion 
28 if the folded-back portion 28 exists at the tip end edge of the 
supporting plate 64a or 64b of the supporting bracket 603 as being 
protruding sideward, as shown in FIGS. 11 to 12, and to insert the tip end 
of each of said deformable portions 618a, 618a'; 618b, 618b' through the 
corresponding small round hole 29a, 29b. 
FIGS. 13 to 17 show the seventh embodiment of the present invention. When a 
strong impact load is given forward (to the left in FIGS. 13, 14 and 17) 
on the steering column 1 through the steering wheel (not shown) and the 
steering shaft 2, the steering column 1 can be freely displaced forward. A 
supported bracket 73 which is made by bending a steel plate having a 
sufficient rigidity is fixed by welding to a middle portion of said 
steering column 1. In the illustrated embodiment this supported bracket 73 
has integrally an installing plate 74, a front bent plate portion 75 
formed by bending the front end edge of the installing plate 74 in the 
middle portion downward, and a rear bent plate portion 76 formed by 
bending the central portion of the rear end edge of the installing plate 
74 downward. A round hole 77 is formed on the central lower part of front 
bent plate portion 75, and a semi-circular cut-away portion 78 is formed 
on the lower edge of the rear bent plate portion 76, respectively. The 
radii of curvature of the round hole 77 and the cut-away portion 78 are 
substantially coincident with the radius of curvature of the outer 
periphery of the steering column 1. The supported bracket having such 
configuration is fixed to the outer periphery of the middle portion of 
this steering column by passing the steering column 1 through the round 
hole 77 and urging said cut-away portion 78 against the outer periphery of 
this steering column 1 and then by welding the inner peripheries of one 
round hole 77 and the cut-away portion 78 with the outer periphery of the 
steering column 1. 
Parts which are at both ends of installing plate 74 and protruding sideward 
more than rear bent plate portion 76 are, respectively, provided with 
cut-away portions 724a, 724c as being open toward the rear end edge of 
installing plate 74 (the right end edge side in FIGS. 13, 14 and 17). 
Then, latching members 79a, 79c are fixed to the inside of these cut-away 
portions 724a, 724c. These latching members 79a, 79c are made of light 
alloy or the like and are latched in such a manner that they are drawn out 
of the cut-away portions 724a, 724c when a large impact load is given onto 
the inside of the cut-away portions 724a, 724c. That is, while a plurality 
of small through-holes 70a, 70c which are respectively formed on both the 
right and left ends of these latching members 79a, 79c are aligned with 
small through-holes (not shown) which are formed on both sides of the 
cut-away portions 724a, 724c in parts of installing plate 74, synthetic 
resins 77a, 77c are filled between these small through-holes. The latching 
members 79a, 79c are not to be drawn from the cut-away portions 724a, 724c 
during a normal driving operation owing to the synthetic resins 77a, 77c. 
However, they are latched in such a manner that they can be drawn when a 
large impact load is given. Also, through-holes 72a, 72c are formed at the 
central portions of the respective latching members 79a, 79c, and the 
supported bracket 73 is supported by a portion 714a fixed to the car body 
with bolts 713a, 713c which are passed through these through-holes 72a, 
72c upward. On the other hand, the front end portion of said steering 
column 1 is slidably supported by a front supporting bracket 715 which is 
supported by and fixed to a portion 714b fixed to the car body. Therefore, 
the steering column 1 is supported as can be displaced forward when a 
forward large impact load is applied to the car body. 
Then, energy absorbing members 716a, 716c which are a feature of the 
present invention are provided between the supported bracket 73 and the 
latching members 79a, 79c, respectively. Each of the energy absorbing 
members 716a, 716c for constituting the steering column assembly of the 
shock absorbing type of the present embodiment is formed into a form shown 
in FIGS. 14 and 16, by plastically bending a metallic wire. These energy 
absorbing members 716a, 716c are provided on both sides of the steering 
column 1 substantially symmetrically. 
Each of the energy absorbing members 716a, 716c is provided with a basic 
portion 717a or 717c and a pair of first and second deformable portions 
718a, 718b or 718c, 718d which are integrally connected to or formed with 
the basic portion 717a or 717c. Each of the basic portions 717a, 717c is 
substantially formed into a U-shape, by bending forward both ends of a 
linear portion 722a or 722c at a right angle or an acute angle. The 
deformable portions 718a, 718b or 718c, 718d of each of the energy 
absorbing members 716a, 716c are formed into a J-shape as a whole by 
providing semi-arch folded-back portions 719a, 719b or 719c, 719d in the 
middle portions of the deformable portions 718a, 718b or 718c, 718d, 
respectively. Note that, in the illustrated embodiment, while one set of 
the deformable portions 718a, 718c, of each of the energy absorbing 
members 716a, 716c is provided at a right angle with respect to the linear 
portion 722a or 722c, the other of the deformable portions 718b, 718d are 
formed to make an acute angle with respect to the linear portion 722a or 
722c. Thus, a distance between the folded-back portions 719a and 719b or 
719c and 719d which are formed in the middle portions of the both 
deformable portions 718a, 718b or 718c, 718d of the energy absorbing 
member 716a or 716c is reduced and the tip ends of both deformable 
portions 718a, 718b or 718c, 718d are provided closer to the steering 
column 1 than the through-holes 72a or 72c. This arrangement, when the 
bolts 713a, 713c are passed through the through-holes 72a, 72c and 
fastened by a spanner or other tool, prevents interference of the tool 
with the other set of deformable portions 718b, 718d. 
In order to realize an effective energy absorbing structure by combining 
with one pair of energy absorbing members 716a, 716c as mentioned above, a 
curved portion 720 is formed at the front end edge of supported bracket 73 
and a pair of small through-holes 721a, 721c are formed on the right and 
left sides of front bent plate portion 75, respectively. That is, a 
cross-sectional shape of a portion at which the upper end edge of the 
front bent plate portion 75 is connected to the front end edge of the 
installing plate 74 is made in an arch shape which is a little smaller 
than the semi arch shape, whereby the curved portion 720 (see FIG. 13) 
which is protruding a little forward from the front side surface of the 
front bent plate portion 75 is formed on the front end edge of the 
supported bracket 73. Also, on the right and left sides of the front bent 
plate portion 75, there are provided the small through-holes 721a, 721c 
which are capable of inserting through parts of the deformable portions 
718a, 718b or 718c, 718d for constituting said energy absorbing member 
716a or 716c, closer to the tip end than said folded-back portions 719a, 
719b; 719c, 719d, respectively. 
A process for constituting the steering assembly of the shock absorbing 
type of the present invention, by combining the supported bracket 73 with 
the energy absorbing members 716a, 716c structured as described above, is 
carried out as described below. First, the tip ends of the deformable 
portions 718a, 718b; 718c, 718d for constituting said energy absorbing 
members 716a, 716c are inserted into the small through-holes 721a, 721c, 
respectively. Then, as shown in FIGS. 13 to 15, the basic portion 717a or 
717c of the energy absorbing member 716a or 716c is fitted on a portion 
which is part of each of the latching members 79a, 79c and is protruding 
from the upper surface of the installing plate 74. While this state 
continues, the linear portion 722a or 722c for constituting the basic 
portion 717a or 717c is abutted upon or opposed to the rear end surface of 
the latching member 79a or 79c. As described above, a process for mounting 
the energy absorbing members 716a, 716c onto the supported bracket 73 can 
be carried out easily and in a short time by utilizing the elasticity of 
these energy absorbing members 716a, 716c. When these energy absorbing 
members 716a, 716c are mounted onto the supported bracket 73 in this 
manner, the bolts 713a, 713c are inserted into the through-holes 72a, 72c 
of the latching members 79a, 79c, and these bolts 713a, 713c are 
threadably engaged with tapped holes provided in the fixed portion 714a to 
the car body, and are fastened further. 
The steering assembly of the shock absorbing type of the present invention 
which is assembled as described above is operated in the following manner 
so as to protect the driver at an accidental collision. At a secondary 
collision, a load is applied frontward (to the left in FIGS. 13 and 14) 
with impact onto the steering column 1 from the steering wheel through the 
steering shaft 2. With this load, the steering column 1 is displaced 
forward together with the supported bracket 73. On the other hand, the 
latching members 79a, 79c remain to be supported on the portion 714a fixed 
to the car body together with the bolts 713a and 713c and are not 
displaced. Therefore, upon start of the displacement of the steering 
column 1, the supported bracket 73 is displaced forward with respect to 
each of the latching members 79a, 79c. Then, after the supported bracket 
73 is displaced forward by the dimension .delta. of a gap 23 which is 
provided between the curved portion 720 and the folded-back portions 719a, 
719b; 719c, 719d (see FIG. 13), the folded-back portions 719a, 719b; 719c, 
719d which are formed in the middle portions of the deformable portions 
718a, 718b; 718c, 718d of the respective energy absorbing members 716a, 
716c are pulled forward by the curved portion 720. 
When the folded-back portions 719a, 719b; 719c, 719d of the energy 
absorbing members 716a, 716c are pulled forward in this manner, these 
folded-back portions are drawn or pushed by the curved portion 720 so that 
these energy absorbing members 716a, 716c are deformed. That is, upon the 
forward displacement of said steering column 1, the folded-back portions 
719a, 719b; 719c, 719d are moved toward the tip ends of these deformable 
portions 718a, 718b; 718c, 718d from the portions at which they are 
originally positioned. Since the energy absorbing members 716a, 716c are 
deformable so as to move the folded-back portions 719a, 719b; 719c, 719d 
toward the tip ends of these deformable portions 718a, 718b; 718c, 718d as 
described above, the impact energy which is applied on the steering wheel 
from the body of the driver upon the secondary collision can be absorbed. 
As a result, the impact given to the body of the driver is mitigated so as 
to protect the driver at the time of secondary collision. 
Especially, in the steering column assembly of the shock absorbing type 
according to the present embodiment, since the energy absorbing members 
716a, 716c are formed by bending metallic wire and the basic portions 
717a, 717c of these energy absorbing members 716a, 716b are fitted on and 
retained by the latching members 79a, 79d, the welding process for 
assembling these energy absorbing members 716a, 716c at predetermined 
portions is no longer necessary. Also, since the energy absorbing members 
716a, 716c are formed by bending the metallic wire, the material is hardly 
wasted so as to improve a yield of the material. Also, no complicated die 
is required for processing the energy absorbing members 716a, 716c, so 
manufacturing cost can be reduced in this respect. Further, the assembling 
work can be easier. Therefore, the efficiency of the assembling work can 
be improved. 
It should be noted that the reason for providing the gap 23 between the 
curved portion 720 and each of the folded-back portions 719a, 719b; 719c, 
719d is to reduce the impact load to be applied onto the body of the 
driver upon the secondary collision as much as possible. That is, a force 
for breaking the synthetic resins 77a, 77b and a force for starting the 
displacement of the installing plate 74 to resist the static friction 
acting between each of the latching members 79a, 79c and the installing 
plate 74 are required for displacing the steering column 1 forward upon 
the secondary collision. These forces are applied only at the moment of 
start of the secondary collision. However, if the "shifting" or "pushing" 
of said folded-back portions 719a, 719b; 719c, 719d is started at the 
moment when these forces are applied, the impact given onto the body of 
the driver at that moment becomes larger correspondingly. By by providing 
the gap 23, it is arranged not to start the "shifting" or "pushing" of the 
folded-back portions 719a, 719b; 719c, 719d at the moment when the 
secondary collision starts. However, if the force required for displacing 
the steering column 1 forward is small, the curved portion 720 may be 
brought into tight contact with the folded-back portions 719a, 719b; 719c, 
719d in a normal condition. 
Next, FIG. 18 shows the eighth embodiment of the present invention. In this 
eighth embodiment, a pair of energy absorbing members 816a, 816b or 816c, 
816d having different dimensions from each other are provided in the right 
and left end potions of an installing plate 84 of a supported bracket 83. 
Since the energy absorbing members 816a, 816b, have symmetrical structures 
to the energy absorbing members 816c, 816d, detailed description thereof 
will be omitted below. Then, it is arranged that a distance .delta.a from 
each of folded-back portions 819a-1, 819a-2 formed on one energy absorbing 
member 816a to a curved portion 820 formed at the front end edge of the 
installing plate 84 should be different from a distance .delta.b from each 
of folded-back portions 819b-1, 819b-2 formed on the other energy 
absorbing member 816b to the curved portion 820 at the front end edge of 
the installing plate 84. In this eighth embodiment in which the energy 
absorbing members 816a, 816b having different dimensions from each other 
are provided in parallel, at the time of a secondary collision, after the 
"shifting" or "drawing" of the folded-back portions 819a-1, 819a-2 of one 
energy absorbing member 816a is started, the "shifting" or "drawing" of 
the folded-back portions 819b-1, 819b-2 of the other energy absorbing 
member 816b is started. Therefore, in this embodiment, it is possible to 
adjust the energy absorbing property of these energy absorbing members 
816a, 816b at the time of the secondary collision. Such adjustment of the 
energy absorbing property can be carried out arbitrarily and very easily 
by changing the positions of the folded-back portions 819a-1, 819a-2; 
819b-1, 819b-2 or changing the linear diameters of both of the energy 
absorbing members 816a, 816b. 
Since the steering column assembly of the shock absorbing type according to 
the present invention is constituted and operated as described above, a 
structure for this apparatus which is capable of mitigating an impact at a 
secondary collision to protect the driver effectively can be obtained at 
low cost.