Note: Descriptions are shown in the official language in which they were submitted.
CA 02093072 2002-10-15
1
CHAIR ASSEMBLY FOR VEHICLE
BACKGROUND OF THE INVENTION
a) Field of the Invention
The present invention relates to a chair assembly
designed to be of maximum comfort and sturdiness in a
vehicle such as a locomotive, which shakes and vibrates
when in motion.
to b) Brief Description of the Prior Art
Heavy vehicles, particularly locomotives of the
type in use today have limited space in the cabin. Thus it
is not easy for the driver or other personnel to get into
or leave the driver's seat. In addition, it is sometimes
necessary for the locomotive driver to look out the side
window for some railroad work such as yard stitching.
Accordingly, it is known to provide a seat which
is slidably mounted on a rail so that the seat can slide
forwardly or rearwardly in the cabin. For example, U.S.
Patent no. 5,118,062 issued on June 2, 1992 to one of the
instant inventors, Mr. Archambault, teaches the use of a
seat attached to the side wall of a locomotive driver's
cabin in a cantilever manner. The seat that can be easily
adjusted horizontally along a rail attached to the side
wall of the cabin, is pivotally mounted on a vertical axis
by means of a threaded shaft extending into a threaded
sleeve which allows the seat to be raised or lowered by
turning the same.
It has been found that such a mounting of the
3o seat with a threaded shaft extending into a threaded sleeve
is unsatisfactory. over a period of time, the threaded
shaft and threaded sleeve tend to wobble and become loose
due to the movement of the locomotive described above.
This becomes a major source of discomfort and back pain
especially when the train is on a long trip.
CA 02093072 2002-10-15
2
Moreover, for the yard switching mentioned above,
the seat disclosed in the above patent cannot be moved
laterally. As a matter of fact, it is mounted at a fixed
distance from the side wall of the locomotive. This
results in an undesirable stretching and twisting of the
back when the driver wants to look out of the side window.
OBJECT AND SUMMARY OF THE INVENTION
An object of the present invention is to provide
a chair assembly for use in the driver's cabin of a
locomotive although the invention is not exclusively
restricted to that application, which obviates at least
some of the above-mentioned disadvantages.
Another object of the invention is to provide a
chair assembly of the above mentioned type, which is
comfortable for drivers of varying physical proportions.
The chair assembly according to the invention as
it is broadly claimed hereinafter, basically comprises:
a chair having a seat and a backrest; and
a chair supporting height-adjustable base including
mounting means to provide rotation, smooth raising and
smooth lowering of said chair whenever desired, and
effective immobility of said chair in any given position,
whereby said chair is wobble and vibration free at all
times.
According to a first important feature of the
invention, the mounting means comprises:
a support bracket adapted to be secured to the
vehicle;
a plate on which the chair is mounted;
a first cylindrical member secured to the center of
said plate and extending downwardly therefrom;
a power cylinder sized to fit precisely into said
first cylindrical member, said cylinder having a lower
end bearing onto a horizontal portion of the support
CA 02093072 2002-10-15
3
bracket, and an upper end bearing onto said plate;
means to operate said power cylinder from the chair to
raise and lower said chair
a second cylindrical member into which said first
cylindrical member precisely fits in a rotatable
manner;
means to retain the second cylindrical member from
slipping downwardly relative to the first cylindrical
member;
a third cylindrical member attached to an upper
portion of said bracket and in which said second
cylindrical member is held in a sliding yet non
rotatable manner;
means to releasably lock the plate to said second
cylindrical member to prevent rotation of the chair
relative to the base whenever desired.
Preferably, the third cylindrical member can be
provided with guide means for facilitating raising and
lowering of the chair. The guide means may comprise:
three equally circumferentially spaced tangential
slots formed in the third cylindrical member close to
each end thereof;
roller bearings mounted in each slot and contacting a
corresponding flattened outer surface portion of the
second cylindrical member, such a contact preventing
the second cylindrical member from rotating relative
to said third cylindrical member; and
means to adjustably secure said roller bearings in
said slots.
According to a second important feature of the
invention that can be used as such or combined with the
first one whenever desired, the chair assembly of the basic
structure disclosed hereinabove may also comprise:
CA 02093072 2002-10-15
4
a slide plate that is part of said mounting means, the
plate having rollers mounted thereon for lateral
rotation;
a chair carriage to which is attached the chair, the
carriage being slidably mounted onto the slide plate
and comprising a pair of laterally extending channels
in which the rollers of the carriage are adapted to
roll; and
lock means to releasably lock the carriage relative to
the slide plate in any desired position, the lock
means comprising:
an elongated bar disposed in one of the channels
between the adjacent rollers and the adjacent
side wall of the carriage, the elongated bar
having a central threaded hole; and
a long shaft journaled in the carriage in a
transversal direction, the shaft having a
threaded portion at one end thereof that engages
the threaded hole,
whereby rotating the shaft in one direction locks
the elongated bar against the rollers to lock the
carriage to the slide plate.
Preferably, the backrest of the chair is
supported by a frame pivotally connected to the seat about
a transversal pivot axis. In this particular case:
one side of the frame has a lower end projecting
downwardly from the pivot axis;
a tension spring is secured to the lower end and to a
front portion of the seat; and
means are provided to adjustably incline the backrest,
biased by said tension spring.
According to still another important feature of
the invention, that can be used as such or combined with
CA 02093072 2002-10-15
4a
any one of the above mentioned features the chair assembly
may further comprise a footrest which vertically adjustable
by way of an adjustment means, the adjustment means
2~93~'~~
comprises:
a foot support,
a pair of arms having lower ends pivotally attached to
the support bracket and upper ends attached to the
5 foot support; and
a second power cylinder having one end pivotally
secured to the bracket and another end secured to the
foot support, this cylinder being actuable by a button
located in the foot support and connected to a switch
l0 means;
whereby one can raise or lower the footrest by
depressing the button with a foot and by pushing
against the foot support, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention and its numerous advantages will be
better understood upon reading the following, non
restrictive description of a preferred embodiment thereof,
given with reference to the accompanying drawings, in
which:
FIG. 1 is a side elevation of a chair assembly
according to the invention, especially designed for use in
a locomotive driver's cabin, showing its base in cross-
section and in an elevated position;
FIG. 2 is an exploded perspective view of the
base, also showing the chair carriage, further showing two
operating handles;
FIG. 3 is a schematic cross-sectional top plan
view of the height adjustable base, also showing the guide
means and the integral adjustment means;
FIG. 4 is a bottom plan view of the chair
carriage and slide plate in center position, also showing
the operating handle;
EIG. 5 is an side elevation view of the assembly
shown in fig. 4;
CA 02093072 2002-10-15
6
FIG. 6 is schematic front elevation view of the
chair assembly attached to the horizontal rail of a side
wall, and
FIG. 7 is a view similar to that of fig. 1,
showing the movement of the backrest and footrest.
DESCRIPTION OF A PREFERRED EMBODIMENT
The chair assembly 1 according to the invention
as shown in figs. 1 and 7 of the drawings, basically
comprises a seat 2, a backrest 3, a pair of armrests 4 and
a footrest 5, all of which are mounted on a height
adjustable base 6. The chair assembly may be fixed to the
floor of a locomotive driver's cabin or, preferably, it may
be attached- as shown in fig. 6- to a seat attachment
assembly 7 as disclosed to the above-mentioned U.S. patent
no. 5,118,062, for fore-aft motion along a rail attached to
a side wall of the cabin, such a motion being controlled by
a lever 8 easily actuable from the chair assembly.
A first essential feature of the invention lies
in the structure and operation of the height adjustable
base 6, which is depicted in figs. 1, 2 and 3. The base 6
comprises an upright rigid L-shaped bracket 9 secured to
the assembly 7 by a plate 9' and bolts 9" as is shown in
fig. 6. Mounted on the bracket 9 at the upper portion
thereof is a large diameter cylindrical member 10. This
member l0 is adapted to receive the following elements: a
small diameter cylindrical member 11; a power cylinder 12
fitted into the member 11; and another cylindrical member
13 of intermediate diameter in which~the cylindrical member
11 of small diameter is fitted. The cylindrical member 13
is sized to fit into the cylindrical member l0 and to be
held in a sliding yet non-rotatable manner within the same
by guide means, as will be disclosed hereinafter. The
power cylinder 12 is preferably an air cylinder although,
in some cases, it can be a hydraulic cylinder. This
CA 02093072 2002-10-15
7
cylinder has a downwardly projecting piston rod 12'. The
lower end of this rod 12' is firmly anchored in the
horizontal portion of bracket 9 by means of a clamp 12".
The upper end of the cylindrical member 11 of
small diameter is welded or otherwise secured to the bottom
surface of a slide plate 14, from which it extends
vertically, downwardly. The power cylinder 12 extends in
the member 11 in a precise fit, as seen in figs. 1 and 3
and bears at each upper end against the slide plate 14.
7_0 Means to operate the cylinder 12 from the chair assembly 1
are provided, consisting of a lever 17 connected to the
actuating mechanism of the power cylinder at the upper end
of the latter. The cylindrical member 11 of small diameter
is free to rotate relative to the power cylinder 12
contained therein and the cylindrical member 13 of
intermediate diameter in which it is precisely fitted. In
order to retain the cylindrical member 13 from slipping
downwardly of its own weight relative to the member 11
contained therein, a retaining ring 19 is provided. The
20 ring 19 has three circumferentially-spaced set screws 19'
which engage corresponding holes provided at the lower end
of cylindrical member 11 (see Fig. 1) . This ring 19 causes
the cylindrical member 13 to move bodily with the member 11
and the cylinder 12 contained therein when the cylinder is
actuated, the whole sliding axially from a lower position
as seen in fig.7 to an uppermost position as shown in fig.
2.
Lock means are provided to lock the slide plate
14 and the chair attached to it, to the cylindrical member
30 13 of intermediate diameter. These means consists of a
collar 18 attached by means of one screw 68 to the bottom
CA 02093072 2002-10-15
8
of the slide plate 14, coaxially relative to the member 11
and 13. The collar 18 which is sized to receive the upper
end of the member 11 of intermediate diameter has a pair of
parallel ears 18' which are formed with a threaded hole 18"
in alignment with each other. Holes 18" are adapted to be
threadedly engaged by a short threaded portion 26'
projecting from a universal-joint member 26. The opposite
end of the member 26 has a threaded bore 26". This bore
receives the threaded end 27' of a shaft 27 to which is
secured a knob 27". Turning the knob 27" in one direction
will tighten the collar 18 around the upper end of the
member 11, while turning it in the opposite direction will
loosen the collar, thereby allowing the slide plate 14 and
the cylindrical member 13 of smaller diameter connected to
it to turn relative to the member 13 of intermediate
diameter and thus relative to the vertical axis of the base
6. Preferably, the shaft 27 is disposed laterally under
seat 2 towards the side wall 28 of the driver' s cabin. The
shaft 27 passes under the lever 17 and through a slotted
tab 29 depending from the right side of seat 2 as best
shown in fig. 6. Lifting of the shaft 27 within the slot of
the tab 29 causes lifting of the lever 17 and thus
actuation of the air cylinder 12.
As described hereinabove, guide means are
provided to slidably hold the cylindrical member 13 within
the member l0 while preventing it from rotating relative to
the bracket 9.
As shown in FIG. 2 and 3, the guide means
comprises, at each end of member l0, three
circumferentially-spaced tangential slots 20 having a
central rectangular recess which communicates with the
CA 02093072 2002-10-15
9
inner surface of the member 10. Each of these slots 20
receives a pair of roller bearings 21 that are mounted on
a same shaft 21' and have their rolling surfaces bearing
against flattened surfaces 13' provided for this purpose on
the exterior surface of the cylindrical member 13. The
roller bearings 21 are kept in position by three vertically
oriented bars 22. Both ends of bars 22 are formed with
grooves shaped to give room to the roller bearing 21 and
hold the extremities of their shaft 21'. The bars 22 are
held by bolts 23 and Belleville washers 24 screwed into the
1. 0
cylindrical member l0.
The above construction is very efficient in use
and eliminates all the wobbling and shaking encountered so
far with other construction. In this connection, it may be
appreciated that the guide means does not only serves as a
guide for the cylindrical member 13. As a matter of fact,
it also serves as an adjustment means should the various
elements begin to wobble or shake. A maintenance person
needs only tighten the bolts 23 until the cylindrical
member 11 and roller bearings 21 are once again in close
20 contact.
Another major feature of the invention lies in
the way the seat 2 is mounted onto the slide plate 14
attached to the upper end of the cylindrical member 11.
Fig. 2 shows the four corners of the slide plate 14
provided with rollers 30 mounted in the fore-aft direction
in bushings 31. The seat 2 is mounted by means of bolts
(not shown) onto a seat carriage 33 including a rectangular
plate provided with holes 32 for receiving the seat
mounting bolts. This plate has integral lateral walls 33'
30 and inwardly extending flanges 33" defining a pair of
opposite lateral channels 34. The rollers 30 are adapted
to roll within the channels 34. Thus, the carriage 33 can
slide from side to side in a side aft direction.
CA 02093072 2002-10-15
9a
Releasable lock means are provided to position the carriage
33 and the chair connected thereto relative to the slide
plate 14. These lock means comprises an elongated bar 35
located in one of the channels 34 and having a central
threaded hole 36 transversal to the carriage. A long
shaft 37 is journaled in bushings 38 fixedly secured to
each side wall 33' and has an endmost threaded portion
engaged in the hole 36. A knob 39 easily actuable from the
chair is provided to rotate the shaft 37. It will be clear
209392
. 10
that turning the shaft 37 in one direction will bring the
bar 35 into locking contact with rollers 30, thus
immobilizing the carriage 33. Turning the knob 39 in the
opposite direction releases the carriage. One may also
understand that the shaft 37 that extends across the slide
plate 14 above the same, acts as a locking means and
prevents this plate 14 from moving out of the carriage 33.
Indeed, it extends across the path of the rollers 30, as is
shown in Fig. 5.
Means to center the carriage 33 are further
provided, consisting o.f a spring-loaded ball 4o secured to
the underside of carriage 33 and which snaps into a
perforation 41 in slide plate 14.
In the embodiment shown and described
hereinabove, the chair has been shown mounted onto the
chair carriage 33 so as to move therewith in a side - aft
direction. It is worth mentioning however that the chair
could also be mounted onto the chair carriage 33 so as to
move therewith in the fore-aft direction. For this
purpose, one has only to attach the seat carriage 33 onto
the bottom of the seat after having oriented the same in a
direction that is perpendicularly to the one shown in the
accompanying drawings. Switching of the seat motion from
the side-aft to the~fore-aft direction can be made easily,
thanks to attachment bolts insertable into the holes 32
(see Fig. 2), which are easily accessible from the bottom
of the chair. This of course adds to the versatility of
the chair assembly according to the invention.
A third feature contemplated by the invention
lies in the structure of the backrest and footrest that are
both adjustable.
As it better shown in Fig. 7, the backrest 3 is
attached to a frame 42 having a pair of support struts.43
transversely pivotable at 44 behind the seat 2. The lower
end of one of the struts 4~ has an outwardly projecting pin
CA 02093072 2002-10-15
I1
45 that extends through a slot 47 formed in a flange 48
secured to the chair carriage 33 on the left side of the
chair. The free end of the pin 45 is threadedly engaged in
a tightenable knob 46. The end of the left strut 43 has
attached thereto a tension spring 49 that is secured to the
front of the frame 2~ of the seat 2. As clearly shown in
fig . 7 , the backrest may thereby be pivoted from an upright
vertical position to an inclined position of approximately
115 degrees by unscrewing the bolt 46 and pushing on the
backrest. The backrest may of course be set in any
position between these two limits by screwing again the
bolt 46, holding of the backrest to the vertical position
being "automatically" achieved thanks to the spring 49
which permanently urges the backrest back to this vertical
position.
As is shown in Figs. 6 and 7, the chair assembly
1 may also be provided with an adjustable footrest 5
including a foot support 51 secured to the upper ends of a
pair of parallel support arms 57 pivotally mounted at 56 to
the base 6. The foot support 51 has a depressible button
52 that upwardly projects therefrom substantially in its
center. The latter is connected to a switch device 53,
which in turn actuates the piston of another power cylinder
54, which is preferably an air cylinder although use could
also be made of a hydraulic cylinder under certain
circumstances. The end of the piston rod 54' of the
cylinder 54 is pivotally attached to the foot support 51.
The other end of the air cylinder 54 is pivotally attached
to a pair of pivot lugs 55 mounted onto the base below the
3o attachment points 56 of the support arms 57. As can be
appreciated the driver only has to press on the button 52
with his or her feet to raise and lower the footrest
according to his or her leg length.
Preferably also, each armrest 4 is mounted on a
telescopic rod 58 that is verticallly ajustable relative to
CA 02093072 2002-10-15
12
support rods 59 integral to the frame of the seat 2 (see
Fig.l ~. Fixation of the rods 58 relative to the rods 59
can be achieved with one or more bolts 61 insertable into
holes provided for this purpose in the rods. This makes it
possible for the driver to easily adjust the armsrests 4 to
any desired height. Morover, each armrest is preferably
connected by a pivot 50 to the corresponding rod 58 so ws
to be upwardly pivotable about this pivot 50 to make easier
the access to the seat 2.
