Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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CEILING MOUNTED DISPLACEABLE SUPPORT ARM
FOR SUSPENDING A DEVICE
TECHNICAL FIELD
The present invention relates to a support
arm for attaching a device in a suspended manner
along a rail and wherein the support arm may be
displaced and locked in a desired position along the
rail by actuating a release mechanism, and wherein
the device supported by the arm may be rotatably
displaced and locked in a desired position by further
actuation of the release mechanism in a different
direction, both these functions being made possible
by the use of a single hand of a user person.
Particularly, but not exclusively, the
support arm is for attaching a medical device in a
suspended manner and displaceable along a guide rail
which is secured to a ceiling of a patient's room of
an ambulance, whereby the attendant may displace the
device to a desired position for use while attending
to a patient or while bracing himself with his free
hand.
BACKGROUND ART
It is known to attach devices in a
suspended manner by a support arm and particularly
medical devices or similar objects. Some of these
attachment devices may include stationary arms or
hook means, such as that disclosed in U.S. Patents
4,273,374 or 4,339,146, and for use inside
ambulances. It is also known to displace a support
arm along a guide rail fixed to a ceiling and having
attachment means whereby the device can be rotated or
else the rail rotated to angulate the device. Such
further devices are for example described in U.S.
Patents 4,738,369 and 5,165,647. A disadvantage of
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many of these devices is that the support arm is
often unstable and it is necessary for a user person
to use both hands to operate two or more attachment
mechanisms whereby to locate the device to a usable
position. Many such attachment means are not
practical when such devices are used inside
ambulances which are in motion and wherein the
attendant who is sitting in the ambulance has to care
for the patient as well as to manipulate the device.
Medical devices suspended from the ceiling of a
patient's room in an ambulance are subjected to all
sorts of forces and shocks generated by the rapid
movement and braking of the vehicle or road
conditions on which the vehicle is being displaced.
This imparts abrupt shocks to the attendant as well
as to the support mechanism to which the device is
connected. This often results in injury to the
attendant as well as to the patient who is being
transported to hospital and most often under
emergency conditions.
There is therefore a need to provide a
support arm for attaching a device in a suspended
manner and wherein the support arm, as well as the
device, may be displaced to a desired position by an
actuating mechanism which is operable by a single
hand of the operator while maintaining failproof
suspension of the device.
SUMMARY OF INVENTION
It is a feature of the present invention to
provide a support arm for attaching a device in a
suspended manner and which substantially overcomes
the above-mentioned disadvantages of the prior art.
Another feature of the present invention is
to provide a support arm for attaching a device in a
suspended manner and wherein the support arm is
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provided with an actuating sleeve which when rotated
in a first direction causes the support arm to be
disengaged with a support rail and reengaged by brake
means at a desired position along the rail when the
sleeve is released.
Another feature of the present invention is
to provide the support arm for attaching a device in
a suspended manner and wherein when the sleeve is
rotated in an opposite direction, it causes a support
bracket on which a device is attached to the bottom
end of the support arm to be rotated to a desired
position and upon release of the actuating sleeve it
is automatically locked at such desired position.
According to the above features, from a
broad aspect, the present invention provides a
support arm for attaching a device in a suspended
manner. The support arm comprises displaceable
attachment means secured to a top portion thereof to
displace the arm along a guide means. Brake means is
provided at the top end of the support arm.
Actuating means is provided for releasable engagement
of the brake means to arrest the arm at a desired
location along the guide means. Connecting means is
rotatably secured to a bottom portion of the support
arm and adapted to secure a device to be supported by
the support arm. A locking mechanism is actuable by
the actuating means to unlock the connecting means to
permit the device to be rotatably displaced to a
desired position and locked at such desired position.
According to a further broad aspect of the
present invention there is further provided a brake
drum mechanism associated with the locking mechanism
to provide torque damping of the connection of the
device to the bottom end of the support post.
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BRIEF DESCRIPTION OF DRAWINGS
A preferred embodiment of the present
invention will now be described with reference to the
accompanying drawings in which:
FIGURE 1 is fragmented perspective view of
the construction of the support arm of the present
invention for supporting a device suspended from a
top guide rail;
FIGURE 2 is an enlarged fragmented view
illustrating the construction of the rotatable
actuating sleeve at the bottom end of the post and
the internal actuating mechanisms to actuate the top
brake pad and the bottom locking mechanism;
FIGURE 3A is a simplified view illustrating
the operation of the torque damping means secured in
the base of the support arm to dampen torque
generated by the device supported at the bottom end
of the support arm when subjected to external forces;
FIGURE 3B is a simplified side view
illustrating the interconnection of the discs of the
torque damping means;
FIGURE 4 is a simplified fragmented
perspective view illustrating the operation of the
brake actuating mechanism; and
FIGURE 5 is a simplified fragmented
perspective view illustrating the operation of the
locking mechanism.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, there is
shown at 10 the support arm of the present invention
for attaching a device 11 suspended from a guide rail
12. Particularly, but not exclusively, the guide
rail is secured to the ceiling of a patient's room in
an ambulance (not shown). The device 11, in this
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application, is a medical device, such as a pulse
monitor or any other medical device that needs to be
suspended and displaceable inside the patient's room
before and often during the transportation of a
patient and particularly in emergency situations.
As herein shown, the support arm is an
elongated tubular member 13 of circular cross section
and secured at a top end to a displaceable attachment
means in the form of an attachment plate 14. The
plate is provided, on a top wall 14' thereof, with
guide rail engaging means in the form of two pairs of
spaced apart guide sheaves 15 which are spaced apart
and secured above the top wall 14 on a respective
side of the support arm. The sheaves 15 are mounted
about support post 16 and freely rotatable thereabout
whereby the support arm 10 may be displaced along the
rail 12 in an effortless manner.
As herein shown, brake means in the form of
a composite brake shoe 17 which protrudes from the
top end 18 of the tubular member 13 for engagement
with the underface 12' of the guide rail 12 which
passes thereover whereby to arrest the support arm 10
against the lower face 12' of the guide rail. A
brake actuating mechanism 19 is disposed in a lower
section 20 of the support arm 10 and is connected to
the brake shoe 17 by an internal actuating rod 21.
The brake actuating mechanism 19 is provided with a
torsion spring 22 which maintains a transverse
follower pin 26 secured to the lower end of the
actuating rod 21 and biased at its bearing ends 26'
in a top end 27" of opposed angled guide slots 27 and
27', as shown in Fig. 4. The follower pin 26 extends
at opposed bearing ends 26' through a top end 68' of
opposed vertical guide slots 68 provided on the
tubular member 13, as shown in Fig. 2. The torsion
spring 22 therefore maintains the actuating rod in an
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upwardly biased position whereby to displace a brake shoe
support plate 28 upwardly from its seated engagement with a
support ring 30. A pin connection 21' connects the top end of
the rod 21 to the support plate 28. A helical spring 29 sits
on the support ring 30 to limit the downward travel of the
brake shoe support plate when the follower pin 26 is displaced
to a lower end section 27 "' of its arcuate opposed guide
slots 27 and 27' by rotation of said actuating sleeve 23 in a
clockwise direction as indicated by arrow 24.
As herein shown the brake shoe 17 sits on a circular disc
17, and is provided with a conical bottom face 31 supported
on a cbncave conical cavity 32 of the brake shoe support plate
28 for close frictional fit with said conical bottom face.
The conical cavity 32 and the conical bottom face 31 provide a
forced damping connection to dampen lateral forces when the
support arm is subjected to a lateral load. Accordingly, when
the support arm is provided with a lateral load, as indicated
by arrow 33, the brake shoe support plate will have a tendency
to move along the direction of arrow 33 and because the brake
shoe 17 is in frictional engagement with the lower face 12' of
the guide rail 12, the brake shoe 17 and the brake shoe
support plate 28 will slide in friction fit along both conical
faces to try to separate. Because these faces are conical the
resisting force will build up as the brake shoe 17 is squeezed
to resist the lateral load thereby providing a damping action.
It can be seen that a helical spring 34 also protrudes
from above a top braking surface 17' of the brake shoe 17 and
this spring is provided to exert a downward force on the brake
shoe 17 to prevent the top surface 17' of the brake shoe 17
from adhering to the lower face 12' of the guide rail 12. The
gap 35 between the top end of the ring 30 and the support
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plate 28 limits the downward travel of the brake shoe relative
to the support ring 30.
Figure 4 is a schematic illustration showing how the
transverse follower pin 26 is supported between the guide
slots 27 and 27' provided in the inner sleeve 25 secured to
the actuating sleeve 23. By rotating the sleeve 23 in a
clockwise direction as indicated by arrow 69, it will cause
the pin 26 to move downwardly along the central axis 35 and
along the vertical guide slots 68, as indicated by dotted
lines, to pull the internal actuating rod 21 downwardly in the
direction of arrow 36 until the bearing ends 26' reach the
bottom end 27" of the guide slot 27.
As shown in Figure 1, the torsion spring 22 is secured at
one end to a follower pin coupling 37 and at another end 38 to
the lower section of the tubular member 13 (not shown) whereby
to bias the transverse follower pin in the upper part of the
angulated guide slots 27 and 27' and vertical guide slots 68 .
As also herein shown the internal actuating rod 21 is located
within an inner cylinder chamber 67 which is disposed between
the support ring 30, at its upper end, and a support ring 39
secured to the inner face of the elongated tubular member 13.
As shown in Figures 2, 3A and 3B, a locking mechanism 40
is housed in a bottom end of the elongated tubular member 13
and actuable by the actuating sleeve 23 to unlock a connecting
bracket 41 from the bottom end of the support arm whereby to
permit a 360 pivotal rotational displacement of the
connecting bracket 41 and its device 11 whereby the device may
be positioned at a desired angular
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position relative to the bottom of the support arm
10.
The locking mechanism 40 comprises a
pressure spring 42 held in compression between a
brake pad support disc 43 at a lower end, and a
teflon disc 44 supported under a displaceable disc
45'. The brake pad support disc 43 is biased against
a brake drum mechanism 45 secured to the connecting
bracket 41 and which extends into the bottom section
of the support arm. A connecting post 46 is engaged
with the brake pad support disc 43 at an upper end
through the slot 47 and secured at its bottom end by
a connecting pin 48 to the connecting bracket 41.
As is also shown in Figures 2 and 5, the
locking mechanism is further provided with a follower
member 49 which extends at opposed bearing ends 51
through a lower end 50 of opposed vertical guide
slots 50, provided in the elongated tubular member 13
for unobstruction thereof, and angulated guide slots
52 and 52' at opposed ends and located in the inner
sleeve 59. When the actuating sleeve 23 is at its
position of rest, the follower member 49 is engaged
at its opposed bearing ends 51 at the lower end of
their respective angulated guide slots 52 and 52' and
vertical guide slots 50 shown in dotted lines, as
shown in Figure 5. In this manner the pressure
spring 42 is compressed applying downward pressure on
the brake pad support disc 43, causing the rubber
disc 53 associated with the brake pad support disc 43
to be frictionally engaged with the top braking
surface 54 of a top torque damping disc 55 of the
brake drum mechanism 45. The brake drum mechanism
45, as shown in Figs. 3A and 3B, also includes a
bottom torque damping disc 56 which is connected to
the base of the tubular member 13 and both the discs
55 and 56 are in facial engagement with one another
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along mating radially sloped formations 57 and 57',
respectively, whereby to prevent rotation of the
connecting bracket 41. The operation of the torque
damping connection of the brake drum mechanism will
be described later.
In order to remove pressure from the brake
drum mechanism 45 to thereby release the frictional
engagement between the rubber disc 53 and the top
braking surface 54 of the top torque damping disc 55,
it is necessary to rotate the actuating sleeve 23 in
a counterclockwise direction as indicated by arrow 58
to impart a rotation to the inner sleeve 59 secured
to the actuating sleeve 23 to remove the downward
pressure on the follower member 49 by causing the
opposed cylinder ends 51 of the follower member to
relocate themselves in the upper ends of their
respective angulated guide slots 52 and 52' and
vertical guide slots 50, as shown in Figure 5. This
upward movement of the follower member 49 removes the
biasing pressure on the pressure spring 42 making it
possible for the brake pad support disc 43 to rotate
about the top face of the top torque damping disc 55
with the rubber disc 53 now in non-pressure or in
sliding fit therewith. Accordingly, the connecting
post 46, which is secured to the connecting bracket
41, is free to rotate within the braking mechanism 40
with the brake pad support disc 43 also being freely
rotatable therein.
As shown in Figures 3A and 3B, the torque
damping discs 55 and 56 are in facial engagement
along mating radially sloped saw tooth-like formation
57 and 57' whereby when the connecting bracket 41
and/or the device 11 secured thereto is subjected to
a torque force caused by load shocks imparted to the
top torque damping disc 55, a rotation will be
imparted to the lower disc causing it to rotate with
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respect to the lower torque damping disc 56 and
through the slope formations 57 and 57' apply an
upward increasing force on the upper disc 55.
However, as seen in Fig. 3A, the upper disc 55 is
limited from upward displacement, by an abutment ring
60 immovably secured to the tubular member 13, a
predetermined distance above the brake pad support
disc 43 so as to limit the upward travel of the top
torque damping disc as it rotates with respect to the
bottom damping disc. This space "y" between the
abutment ring 60 and the top wall of the brake pad
support disc 43 is illustrated by reference numeral
61 in Figure 3A. The gap "y" defined by the space 61
is also smaller than the gap "x" defined between the
bottom end 62 of the radially sloped formations 57 or
57' and the peak opposite end 63 thereof (see Fig.
3B) whereby the torque damping discs 55 and 56 cannot
separate.
The actuating sleeve 23 may be provided
with finger engaging formations 64 thereabout or
alternatively may be provided with a rubber-like
gripping surface to permit non-slip engagement
thereof by the user's hand. As herein shown, a lock
ring 65 also interconnects the actuating sleeve 23 in
rotational displacement with respect to the elongated
tubular member 13. The connecting bracket 41 may
also have a different shape and as herein shown it is
a plate provided with through holes 66 to receive
fastening bolts to secure a device or instrument 11
thereto, see Fig. 1.
It is within the ambit of the present
invention to provide any other obvious modifications
of the preferred embodiment described herein, provide
such modifications fall within the scope of the
appended claims.
