U.S. patent application number 10/528327 was filed with the patent office on 2006-04-20 for means for compressing tubes and the like.
Invention is credited to Jagmohanbir Singh Dillon, William Leonard Mobbs, Craig Douglas Wilson.
Application Number | 20060081647 10/528327 |
Document ID | / |
Family ID | 28047373 |
Filed Date | 2006-04-20 |
United States Patent
Application |
20060081647 |
Kind Code |
A1 |
Wilson; Craig Douglas ; et
al. |
April 20, 2006 |
Means for compressing tubes and the like
Abstract
A device (10) for stripping fluid from a tube (40) is provided
that is of use in stripping blood from bloodlines after the
collection of blood from donors. The device is preferably hand-held
and battery-powered, having a fixed driven roller (18), a moveable
idle roller (20) and a tube guide (22) extending cantilever-fashion
from one end thereof. The idle roller (20) can be moved toward the
fixed and driven roller (18) to form a nip therebetween which
pinches the tube (40) and draws it through the nip when the driven
roller (18) is rotated. Idle roller (20) is moveable in a slot (50)
and in direction which is never coplanar with the plane (Y) that
contains the axes of the rollers (18 & 20). The angle .theta.
between the direction of movement of the idle roller (20) and the
plane (Y) containing the axes of the rollers when the nip is formed
can vary between about 30 and 90 degrees.
Inventors: |
Wilson; Craig Douglas; (New
South Wales, AU) ; Dillon; Jagmohanbir Singh;
(Capital Territory, AU) ; Mobbs; William Leonard;
(Capital Territory, AU) |
Correspondence
Address: |
Mark A Wilson;Wilson & Ham
PMB 348
2530 Berryessa Road
San Jose
CA
95132
US
|
Family ID: |
28047373 |
Appl. No.: |
10/528327 |
Filed: |
September 19, 2003 |
PCT Filed: |
September 19, 2003 |
PCT NO: |
PCT/AU03/01239 |
371 Date: |
March 18, 2005 |
Current U.S.
Class: |
222/102 |
Current CPC
Class: |
A61M 1/83 20210501 |
Class at
Publication: |
222/102 |
International
Class: |
B65D 35/28 20060101
B65D035/28 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 25, 2002 |
AU |
2002951618 |
Claims
1. A device for expressing fluid from a tube by drawing the tube
through the nip formed between a first roller and a second roller
respectively having first and second axes, the second roller being
moveable toward the first to form the nip and away from the first
to facilitate placement and removal of the tube from between the
rollers, the device being characterized in that: the second roller
is mounted for movement toward and away from the first roller in a
direction that is at an angle to the plane containing the axes of
the rollers; that is, in a direction that is not coplanar with the
axes of the rollers.
2. A device for expressing fluid from a tube according to claim 1
wherein said angle is between 30 and 90 degrees when the nip
between the rollers is formed.
3. A device for use in stripping fluid from a length of tube, the
device having first and second rollers that are respectively
rotatable about first and second axes of rotation and which can be
brought together on opposite sides of the tube to form a nip
between the rollers and a pinch-point in the tube, and the device
having drive means for rotating at least one of the rollers so as
to move the pinch-point longitudinally along the tube to expel
fluid from the tube, the device being characterized in that: the
rollers are brought together to form the nip by moving the second
roller toward the first in a direction that has a longitudinal
component with respect to the tube, when the device is in use.
4. A device according to claim 3 wherein: the device has a body
that includes a frame, the first and second rollers are mounted on
the frame so as to extend cantilever-fashion from the body, first
drive means is provided within the body and fixed to the frame for
rotating the first roller about its axis, the axis of the first
roller being fixed with respect to the frame, the second roller is
an idle roller mounted for free rotation about its axis on mounting
means that is moveable with respect to the frame so as to be
adapted to move the second roller relative to the first roller, and
second drive means is provided within the body and fixed to the
frame, said second drive means being adapted to move said mounting
means, together with the second roller mounted thereon, with
respect to the frame.
5. A device according to claim 4 wherein: the first roller is
mounted for rotation by a shaft that extends from one end of the
roller and is coupled to the first drive means so that the first
roller can be rotated by the shaft, said mounting means is in the
form of a yoke that straddles said shaft, the yoke having two
opposing arms with the shaft arranged therebetween and the yoke
being slidably mounted on the frame within the body, the second
roller is mounted on one of said arms of the yoke, and said second
drive means is coupled to the other arm of the yoke to effect the
movement of the mounting means.
6. A device according to claim 5 wherein: a leadscrew is mounted
for rotation on the frame and is engaged with a nut that is secured
to said other arm of the yoke so that rotation of the leadscrew
will effect movement of the mounting means and the second roller
relative to the frame, said second drive means is rotatably coupled
to the leadscrew so as be able to rotate the leadscrew in one
direction so as to move the yoke to carry the second roller toward
the first roller and in the other direction so as to move the yoke
to carry the second roller away from the first roller.
7. A device according to claim 6 wherein: a worm wheel is fitted to
one end of the leadscrew and a worm that engages the leadscrew is
fitted to a second shaft that is coupled to the second drive means
for rotation thereby in either direction.
8. A device according to claim 7 wherein: a guide is provided for
constraining the lateral movement of the tube and for ensuring its
longitudinal movement.
9. A device according to claim 1 wherein: the device has a body
that includes a frame, the first and second rollers are mounted on
the frame so as to extend cantilever-fashion from the body, first
drive means is provided within the body and fixed to the frame for
rotating the first roller about its axis, the axis of the first
roller being fixed with respect to the frame, the second roller is
an idle roller mounted for free rotation about its axis on mounting
means that is moveable with respect to the frame so as to be
adapted to move the second roller relative to the first roller, and
second drive means is provided within the body and fixed to the
frame, said second drive means being adapted to move said mounting
means, together with the second roller mounted thereon, with
respect to the frame.
10. A device according to claim 9 wherein: the first roller is
mounted for rotation by a shaft that extends from one end of the
roller and is coupled to the first drive means so that the first
roller can be rotated by the shaft, said mounting means is in the
form of a yoke that straddles said shaft, the yoke having two
opposing arms with the shaft arranged therebetween and the yoke
being slidably mounted on the frame within the body, the second
roller is mounted on one of said arms of the yoke, and said second
drive means is coupled to the other arm of the yoke to effect the
movement of the mounting means.
11. A device according to claim 10 wherein: a leadscrew is mounted
for rotation on the frame and is engaged with a nut that is secured
to said other arm of the yoke so that rotation of the leadscrew
will effect movement of the mounting means and the second roller
relative to the frame, said second drive means is rotatably coupled
to the leadscrew so as be able to rotate the leadscrew in one
direction so as to move the yoke to carry the second roller toward
the first roller and in the other direction so as to move the yoke
to carry the second roller away from the first roller.
12. A device according to claim 11 wherein: a worm wheel is fitted
to one end of the leadscrew and a worm that engages the leadscrew
is fitted to a second shaft that is coupled to the second drive
means for rotation thereby in either direction.
13. A device according to claim 12 wherein: a guide is provided for
constraining the lateral movement of the tube and for ensuring its
longitudinal movement.
14. A device according to claim 1 wherein: a guide is provided for
constraining the lateral movement of the tube and for ensuring its
longitudinal movement.
15. A device according to claim 3 wherein: a guide is provided for
constraining the lateral movement of the tube and for ensuring its
longitudinal movement.
Description
TECHNICAL FIELD
[0001] This invention relates to devices and methods for use in
compressing hollow flexible tubes to express matter contained
therein. It is particularly, but not exclusively, suited to
stripping blood from tubes that are connected to blood packs.
BACKGROUND
[0002] Our prior international patent application PCT/AU01/0400
disclosed devices and methods of this nature, with particular
application for the stripping of blood lines. It also reviewed
relevant prior art and the uses for such devices. Some of the
devices disclosed in our prior application were hand-held and
self-powered. This invention is particularly concern with further
improvements to the design and operation of such devices.
[0003] The devices disclosed and illustrated in our prior patent
application each had a pair of rollers that could be brought
together to form a nip to pinch the tube and then rotated to draw
the tube through the nip, thereby stripping or expressing the
contents of the tube. If desired, the rotation of the rollers could
be reversed and the tube driven in the opposite direction to allow
it to fill with mixed blood and anticoagulant from the blood bag.
After repeating the stripping and refilling steps one or two times,
the full tube can be heat-sealed to form a sausages-string of
sample pouches of blood that are very useful for use in
cross-matching at a later date. Of course, at the end of the
stripping procedure, the rotation of the rollers is stopped and the
rollers are moved apart to allow the tube to be removed from the
stripping device.
[0004] As is conventional in rolling mills and calendaring devices,
the axes of the rollers of our prior application always remained in
a plane that was orthogonal to the direction of travel of the
material therebetween while the rollers are moved together and
apart. We have now found that, in handheld tube-stripping devices
where power is limited, undesirable strain and power consumption is
involved when forming the nip, and/or it is difficult to obtain the
desired pressure or gap between the rollers at the nip.
OUTLINE OF THE INVENTION
[0005] The present invention is based upon the realization that
design and performance advantages in tube stripping devices,
especially compact hand-held devices, if the roller movement that
forms the nip is always at an angle to the plane that contains the
axes of the rollers. For example, the angle between the roller
movement and the plane of the roller axes when the nip is formed
can be anywhere between about 30 degrees and 90 degrees. This is to
be contrasted with conventional roller systems where the roller
movement is always coplanar with the plane of the roller axes; that
is, the angle between the direction of roller movement and the
plane of the axes when the nip is formed is zero.
[0006] Thus, from one aspect, the present invention includes a
device for expressing fluid from a tube by drawing the tube through
the nip of a pair of rollers having spaced axes of rotation, one of
the rollers being moveable toward the other to form the nip and
away from the other to facilitate placement and removal of the tube
from between the rollers, the device being characterized in that
the moveable roller moves toward and away from the other in a
direction that is at an angle to the plane that contains the axes
of the rollers.
[0007] A tube guide may be used to guide the tube as it enters and
or leaves the nip of the rollers and to assist in keeping the tube
in the central portion of the nip. The tube is thus constrained to
follow a defined path between the rollers and the guide when it is
being stripped, and it is convenient to say that this path is
`longitudinal` with respect to the tube since the tube is flexible
and will seldom be straight along its entire length.
[0008] Thus, from another aspect, the invention comprises a device
for use in stripping fluid from a length of tube using rollers that
can be brought together on opposite sides of the tube to form a nip
between the rollers to compress the tube, at least one of the
rollers being rotationally driven to draw the tube through the nip
so as to expel fluid from the tube, the device being characterized
in that the rollers are brought together to form the nip by moving
one toward the other in a direction that has a longitudinal
component with respect to the tube.
[0009] Conveniently, the rollers and the guide extend
cantilever-fashion from the body of the device and one of the
rollers is driven by first drive means and the other roller is
allowed to idle, the idler roller being supported on mounting means
that can be moved toward and away from the driven roller (to close
and open the nip) by second drive means. The mounting means can be
in the form of a yoke that straddles a drive shaft connected to the
driven roller, the idler roller being rotatably mounted on one of
the arms of the yoke and the second drive means being coupled to
the other arm of the yoke to drive it so that the idler roller can
be driven toward or away from the driven roller in the desired
manner. One way of driving the yoke is to employ a leadscrew that
engages with a nut in the respective arm of the yoke, the leadscrew
preferably being rotated by a worm gear that forms part of the
second drive means and mounted on a frame that is fixed relative to
the body of the device.
DESCRIPTION OF AN EXAMPLE
[0010] Having broadly portrayed the nature of the present
invention, one example of a device formed in accordance with the
principles of the invention outlined above will now be described
with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is and external plan view from above of the device of
chosen example, the direction of view being indicated by arrow I on
the end view of FIG. 4.
[0012] FIG. 2 is an external plan view from below of the device of
FIG. 1, the direction of view being indicated by arrow II on the
end view of FIG. 4.
[0013] FIG. 3 is an external side elevation of the device of FIG.
1, the direction of view being indicated by arrow III on the end
view of FIG. 4.
[0014] FIG. 4 is an enlarged end elevation of the device of FIGS.
1-3 with the rollers shown in a partially open position.
[0015] FIG. 5 is a reduced end view of the device of FIGS. 1-4 with
the rollers in the closed position and a tube being pulled
therethrough.
[0016] FIG. 6 is a similar view to that of FIG. 5 but shows a
modified device with an alternative arrangement of rollers in the
closed position.
[0017] FIG. 7 is a general perspective of the mechanism of the
device of FIGS. 1-5.
[0018] FIG. 8 is an enlarged perspective of the mechanism shown in
FIG. 7, with some parts sectioned.
[0019] Referring generally to FIGS. 1-4, the device 10 of the
chosen example is a self-powered, hand-held blood line stripper for
use by blood collection agencies to effect the mixing of the
anticoagulant contained in a full blood pack (not shown) with the
residual blood in the blood line tube (not shown in FIGS. 1-4) so
that sample pouches can be formed. [The procedure concerned was
described in some detail in our prior application.] Device 10 has a
two-piece molded body 12 comprised of left and right parts 12a and
12b, respectively, fitted together at joint line 13. Body 12 has a
head or front portion 14 that houses the roller mechanism (to be
described) and a tail or rear portion 16 that houses a battery (not
shown or described herein). A pair of rollers 18 and 20 and tube
guide 22 project forward cantilever fashion from the front face 24
of body 12 and connector means 26 are provided on the rear end 28
of rear portion 16 for the connection of a battery charger (not
shown or described herein).
[0020] A pair of pads 30 and 32 are affixed to the top of device
10, as shown in FIG. 1, to give the device a more comfortable grip
for the user. The bottom of device 10, shown in FIG. 2, has two
pad-like switches 34 and 36 by which the device can be controlled,
switch 34 having two positions for effecting the movement of
rollers 18 and 20 together or apart, and switch 36 having one
position for effecting the reversal of the roller rotation while
switch 36 is operated. FIG. 3 is a side view of the device showing
side 12a in which a series of LEDs 38 indicate the level of charge
of the battery. FIG. 4 is an enlarged end view of device 10,
showing rollers 18 and 20 in partially open, while FIG. 5 is the
same view (but reduced in scale) showing rollers 18 and 20 in the
closed position and a tube 40 in the nip of the rollers. In FIG. 5,
arrow 42 indicates the direction of movement of tube 40 and arrows
44 indicate the direction of rotation of the rollers when device 10
is being operated as described below. It will be noted that guide
22 constrains tube 40 to move in a generally longitudinal
direction, indicated by arrow 42.
[0021] The normal mode of operation of the device will thus be as
follows: (i) device 10 is held in one hand, (ii) starting with
rollers 18 and 20 apart, the tube 40 is placed in position between
them and under guide 22 using the other hand, (iii) pad switch 34
is then operated by a finger of the first hand to close the rollers
onto tube 40, rollers 18 and 20 being driven forwards (ie, in the
direction of arrows 44) upon activation of switch 34 to close them
so that, when closed, tube 40 is driven longitudinally (with
respect to the tube) in the direction of arrow 42, (iv) upon
reaching the blood bag or sealed needle-end of the tube, pad switch
36 is operated and held down to reverse the roller drive until the
starting point is reached, (v) whereupon pad 36 is released and
rollers 18 and 20 are again driven forwards, and finally (vi), when
sufficient forward and reversing of the rollers had been effected,
pad switch 34 is operated to open the rollers again, automatically
effecting inactivation of the roller drive and allowing tube 40 to
be removed from device 10. This mode of operation is substantially
as disclosed in our prior patent.
[0022] In this example, roller 18 is mounted fixedly relative to
body 12 of device 10 and is driven by first drive means (to be
described), while roller 20 is an idler roller that is moveable
within body 12 toward and away from fixed roller 18, the direction
of movement being vertical, that is, parallel with the joint 13
between the two halves 12a and 12b of body 12 and generally
longitudinal with respect to the tube (when in place, as in FIG.
5). The direction of the movement of roller 20 is also indicated by
a vertical slot 50 formed in the front face 24 of the device to
accommodate the shaft of roller 20 is it moves. From FIG. 5 it will
be seen that the movement of tube 40 during stripping is nearly
vertical (in part because of the constraining action of guide 22)
and that idler roller 20 moves roughly parallel (ie, longitudinal)
with tube 40 during opening and closing of the nip with roller 18.
In FIG. 5, the nip and pinch-point in the tube are coincident and
indicated at X. The roller movement contrasts sharply with
conventional pinch-rolls (including those described in our prior
patent application) where the movement of the roller(s) in forming
the nip is orthogonal to the general direction of travel of
material through the rolls and to the direction of travel at the
pinch point.
[0023] In the arrangement of FIG. 5, rollers 18 and 20 overlap when
viewed in the direction of travel of roller 20 (ie, vertically--see
FIGS. 1 and 2) so that, when the nip X is formed, the plane or line
Y that passes through the axes of the rollers is at a significant
angle .theta.--about 45 degrees in this case--to the movement of
roller 20 as indicated by slot 50. In our experience, angles much
smaller than this are undesirable, though angles as high as 90
degrees are possible, as illustrated by FIG. 6.
[0024] FIG. 6 shows a modified device 10a that has rollers 18a and
20a that do not overlap at all when viewed in line with the
direction of movement of roller 20a, making angle .theta. 90
degrees. Thus, as indicated by the vertical orientations of slot
50a and arrow 42a, tube 40a travels essentially parallel with the
movement of roller 20a (ie., vertically in this case). However, the
geometry of FIG. 6 may not be optimal because the pinch pressure
cannot be adjusted by movement of a limit switch (not shown) that
controls the position of the moving roller in the closed
position.
[0025] It is important to note that the direction of movement of
moveable roller 20 or 20a is never coplanar with the plane Y
defined by the axes of the two rollers 18, 18a and 20, 20a, whether
the rollers are open or closed. This contrasts with the prior art
where the direction of movement of the moveable roller is always
coplanar with the axes of the two rollers. While FIGS. 5 and 6 show
arrangements where the angles between the direction of movement of
the moveable roller and the plane of the roller axes are,
respectively, about 45 and 90 degrees when the nip is formed, we
have found that angles between about 30 degrees and 90 degrees can
be used with advantage.
[0026] Turning now to FIGS. 7 and 8, the mechanism associated with
rollers 18 and 20 will now be described, some portions of the
mechanism being cut away or omitted in FIG. 8 for the sake of
clarity. Fixed and driven roller 18 is attached to a shaft 60 that
is driven directly by a low-voltage electric motor 62 via an
integral planetary gearbox 64, which are mounted on front portion
66a of frame 66. Thus, in this example, shaft 60, motor 62 and
gearbox 64 comprise the first drive means referred to above. The
front portion of shaft 60 is supported for rotation in a bearing 68
that is mounted in a front portion 66a of frame 66. Idler roller
20, however, is mounted for free rotation on a short shaft or stub
axle 70 that is rigidly attached to the bottom of one arm 72a of a
moveable yoke 72 located for vertical sliding movement in frame 66.
In FIG. 8, roller 18 has been cut away to show shaft 70 and the
lower portion of yoke arm 72a more clearly.
[0027] Yoke 72 is driven up and down by means of a vertical
leadscrew 74 that engages a nut 76 fixed in the top of yoke arm
72b, which is bored to take leadscrew 74. The top of leadscrew 74
is mounted for rotation in a bearing 76 fitted into a horizontal
plate 66b that forms part of frame 66, the lower portion of
leadscrew 74 being rotationally and slidingly located by a bearing
78 that is mounted in the bottom part of yoke arm 72b and retained
there by a circlip 80. A worm-wheel 82 is fixed to leadscrew 74
below yoke arm 72b, the lower extremity of leadscrew 78 being
mounted for rotation in a bearing 84 fitted in a lower horizontal
plate 66c of frame 66. Worm-wheel 82 is engaged by a worm 86 that
is mounted on a horizontal shaft 88 that is driven by a second
low-voltage motor and gearbox assembly 90, the front end of shaft
being located in a bearing (not shown) located in front element 66a
of frame 66. Thus, in this example, the second drive means can
encompass motor 90, shaft 88, worm and gear 86 and 82 and leadscrew
74 and nut 76, either in their entirety or in part.
[0028] It will be seen that rotation of shaft 88 by motor 90 in one
direction or the other will effect the rotation of leadscrew 74 in
nut 76 (via worm drive 82/86) and cause yoke 72 to be driven up or
down, carrying idler roller 20 with it. The slot 50 in frame 66a
(visible in front face 24 of device 10) permits this movement, as
already noted. Though not shown in the drawings, it is desirable
that both the up and down movements of yoke 72 be set by limit
switches connected in the power circuit to motor 90. This technique
is well known in the art and can be used to effect fine adjustment
of the upper limit of travel of roller 20 to set the roller nip X
to the desired gap. It will also be seen that, because shaft 60 (by
which fixed roller 18 is driven) passes through the central opening
92 of yoke 72, it and roller 18 are free to rotate whatever the
position of the yoke. [As shown in FIG. 8, yoke 72 and roller 20
are near the lower limit of their travel.]
[0029] While the above example illustrates a device that is
particularly useful for stripping blood lines, it will be
appreciated that disclosed principle of roller movement can have
application elsewhere and that many changes can be made to this
example without departing from the scope of the mechanism as
defined by the following claims. For example, the device need not
be battery powered as power can readily be supplied to the drive
means via a trailing electrical lead.
* * * * *