Note: Descriptions are shown in the official language in which they were submitted.
CA 02472609 2004-06-28
MBM File No. 1263-103
- PIPE CLEARING SYSTEM AND DEVICE
FIELD OF INVENTION
The present invention pertains to the field of devices for use with sewers and
pipes and in
particular to a device and system for cleaning and clearing obstructions
inside a pipe.
BACKGROUND
Pipes for the transport of sewage material and other similar purposes have
been in use for
many years. These pipes have generally a cylindrical shape, and may be formed
from
concrete, plastic, steel or other materials. The sizes of these pipes vary
from sewer pipes
greater than 12 feet in diameter to some less than 3 inches in diameter.
Such pipes, particularly the smaller pipes, can often, in the course of normal
use, become
blocked. Blockages often occur due to factors such as the accumulation of dirt
or grease,
which results in gradually narrowing the pipe until total blockage is present.
Such blockages
commonly occur in sewer pipes that sag or have a "sump" due to ground shift,
as well in
sewer pipes having corrosion, cracks, separated joints or misalignment
defects. Blockage
may also occur where some obstacle, for example cloth, is flushed into the
system. A further
common occurrence is the intrusion of roots from trees and bushes, wherein a
crack in a pipe
may release liquid or humidity, and as a result roots may be attracted to the
area and
eventually enter the pipe. These roots can then build up in matted balls,
creating a stubborn
blockage. Such blockages can create an immediate problem, requiring pipe
clearing services.
In many cases professional or skilled help is required to solve the blockage.
Three general
techniques are presently available, all of which typically require a skilled
operator.
One method is the "spraying" method, which employs the use of a tube or
hydraulic pipe
with a nozzle attachment. Such an attachment may employ one or several spray
heads that
direct the water in the desired directions. A spray head uses jets or fan
sprays, or a
2
CA 02472609 2004-06-28
MBM File No. 1263-103
combination of both. Several difficulties arise with this method. The use of
water will
continue to fill the pipe, and may quickly cause an overflow condition into a
house or other
building. In addition once the device has been inserted into the pipe, there
is little control
over the spray head direction from its original setting prior to insertion in
said pipe.
Strauss in U.S. Patent 4,677,997 discloses a high pressure revolving sewer
cleaning nozzle,
which is attached to a tube and inserted into a pipe. A sled-like skid carries
the revolving
nozzles, rotating to allow full coverage of the sides of the pipe. A nozzle at
the front of the
sled is directed forward to a blockage. Use of a sled may be difficult in
smaller pipes. As
well, the adding of more fluid to a clogged pipe may increase the chance of
flooding.
Another method is the "snake" method, which involves the use of a long
flexible rod,
referred to as a "snake" in the industry. A variety of cutting devices may be
attached to the
end of the snake, including screw threads, wire coils, blades etc, all
designed with the
intention of breaking up a blockage. The snake may be rotated either manually,
or as is more
common, by means of a motor positioned outside of the pipe which turns the
snake rapidly
causing the cutting device to penetrate a blockage.
The snake is a popular method for breaking up blockages, but does have
drawbacks.
Machinery used for rotating the snake while feeding it into the pipe tends to
be very heavy
and bulky. As such, the snake equipment may take up a lot of space in service
trucks, for
example. Furthermore, in addition to being arduous, carrying large and heavy
snaking
equipment can be hazardous both to the person and to property. For example,
carrying large,
heavy snaking equipment indoors, up a flight of stairs, poses a risk of
personal injury as well
as property damage. A professional engaged in sewer pipe clearing who must
carry large,
heavy snaking equipment into remote sites could be exposed to constant risk of
personal
injury and liability for property damage.
Another drawback of using a snake is that the long snake, as it rotates,
constantly scrapes
against the wall of the pipe, causing wear and tear on the pipe. The torque of
the snake may
break weak pipes and fittings. As well, a relatively large amount of energy
may be required
3
CA 02472609 2004-06-28
MBM File No. 1263-103
to turn the entire snake. Also, the snake can twist, causing a delay between
the motor speed
and the cutting device. If the cutting device jams, the cable may twist itself
inside the pipe.
Excessive bending may weaken or permanently damage the snake. In some cases,
the
jamming may cause the snake to break inside the pipe, in which case extensive
labour may
be necessary to retrieve the broken cable, and replacing a broken snake may
also be
expensive. Yet another drawback of the snake method is that it would be
difficult to
effectively install a camera on the snake. The constant rotation along the
entire length of the
snake would make it difficult to obtain a stable image and, furthermore, make
it difficult to
feed an electrical image signal along the snake. As such, the snake is
typically operated
"blindly" by the operator. Visual inspection of the blockage could require,
for example,
stopping the snake, withdrawing it, and inserting a camera tube. Then, to
resume
unblocking, the camera tube must be withdrawn, and the snake reinserted.
Sloter et al. in U.S. Patent 5,222,270 discloses an electromagnetic motor
brake unit for a
rotary drain and sewer router. This unit provides a means for supplying a
snake into a pipe
whilst constantly rotating the snake with its associated cutting device.
A third method, the "remote motor" method, for removing an obstacle in a pipe
is to use
cutting and clearing tools driven by a motor located inside the pipe near the
blockage,
controlled remotely by the operator. Such a motor may be electrically,
pneumatically or
hydraulically powered. The motor may be positioned by means of a rod, for
example a
flexible rod, or other such mechanical system, or may use its own traction
method, with
wheels or other method. Such a motor is able to power cutting blades in a
manner to remove
obstacles, providing multiple blades in a variety of positions.
Holland, in U.S. Patent Application No. 10/OS9,205 (publication number
2002/0102136)
discloses a robotic apparatus operable inside a conduit that may be powered by
means
including hydraulic means. Derlein, in U.S. Patent 5,622,571 describes the use
of a hydraulic
motor in a pipe cleaning system. It describes a mobile power unit with two
hydraulic hose
reels providing hydraulic supply and return lines to a sewer cleaning module.
Wilson, in
U.S. Patent 5,377,381 describes a cleaning system in which a vehicle with
fluid-powered
4
CA 02472609 2004-06-28
MBM File No. 1263-103
drive motor uses a spray head for spraying a liquid.
Elzaurdia in U.S. Patent 5,226,207 describes a sewer unclogger where a grapple
hook or
cutter rotates and is powered either by an electrical motor or a pneumatic
motor which can be
driven by compressed air. The device is pushed through the sewer or pipe by a
rod or snake.
A pneumatic tube is described for supplying compressed air to the pneumatic
motor and also
acts as the snake or push rod to thread the pneumatic motor through the pipe.
The patent also
discloses that a flat bar tape can be used to place the motor or rotator into
the pipe, as a flat
bar tape can be used more effectively since it need not rotate and can provide
resistance to
1o rotation. The patent states that flat bar tapes are less expensive and have
greater tensile
strength for the same weight as coiled snakes.
Crane et al. in U.S. Patent 4,766,631 describe a sewer pipeline hydraulic root
cutter apparatus
in which a hydraulic motor drives a shaft to which is connected a cutting
tool. The device
~ 5 has an inlet for incoming hydraulic fluid. The fluid is released from the
device into the pipe
through a nozzle. The act of adding fluid to a clogged pipe, however may
increase the
chance of flooding. In addition, Long, Jr. in Patent 4,520,524 describes a
remotely controlled
hydraulic cleaner apparatus equipped with a hydraulic motor having a return
conduit for
hydraulic fluid. This form of system, however may not be suitable for smaller
pipes and
20 sewers.
It is known in the prior art to provide a sewer cleaning device mounted on
skids and pushed
through the sewer, wherein the sewer cleaning device has a hydraulic motor,
using high
pressure water, for rotating and cutting to clean the sewer. Such a device is
disclosed by
25 Crane et al. in Patent No. 4,766,631 and by Crane in U.S. Patent No.
4,516,286. It is also
known to provide rotating brushes or cutters driven by an electric motor for
moving through
a pipe for cleaning. This is disclosed in U.S. Patent Nos. 2,497,659 to T. J.
Davis et al.,
2,061,864 to W. T. Wells, 508,380 to F. Gardner, and 4,773,115 to Smith.
3o Generally, existing motor systems tend to be large and therefore suitable
for pipes of large
diameters. For example, the use of tracks is not generally appropriate for
small pipes.
5
CA 02472609 2004-06-28
MBM File No. 1263-103
Known motor systems are generally too large to fit into small pipes. Some
motors may also
be susceptible to jamming if the device encounters mechanical resistance.
Foster in U.S. Patent 6,058,547 describes a device for removing objects from a
constrained
area or pipeline. The motor is mounted on a skid and drives a rotating cutting-
wire, or
"strimming" system of four semi-rigid elements.
Existing technologies to clear obstructions for blocked sewers include the use
of mechanical
rods or cables. Such rods and cables, however, are designed to push or cut
through
obstructions and have limited root cutting capacity.
Other existing technologies to clean building sewers include the use of high
pressure water
nozzles. This technique, however, requires that the obstruction first be at
least partially
unblocked to allow drainage of the sewer to prevent water/sewage back-up. One
example of
t5 an application of this technique is the Flusher TruckTM which pumps water
into the sewer at
13 GPM to 25 GPM, wherein such techniques are designed to remove grease and
debris build
up. The addition of fluid to a clogged pipe, however, can often result in
flooding.
As such there is a need for a device to unblock or clean sewers and other
pipes, which
2o provides a low cost, easy to use, portable, and efficient method of
unblocking pipes. There is
a need for pipe unblocking and cleaning equipment that is compact, lightweight
and portable.
There is a further need for a pipe unblocking and cleaning device which does
not add liquid
to the pipe, so as not to increase the likelihood of flooding. There is a need
for a pipe
cleaning or unblocking device equipped with rotating tools such as cutting
heads, that is
25 capable of providing a relatively stable, non-rotating location on which a
camera may be
mounted. There is a need for a pipe cleaning system that minimizes damage to
the system
due to "jamming" problems, for example when the cutting or clearing device
meets a
unexpectedly large degree of resistance.
SUMMARY OF THE INVENTION
3o An object of the present invention is to provide a pipe clearing system and
device. In
6
CA 02472609 2004-06-28
MBM File No. 1263-103
accordance with an aspect of the present invention, there is provided a pipe
clearing device
comprising: a power transfer unit sized to be accepted within a pipe; at Ieast
two rotary
elements mounted on a leading end of the power transfer unit, said at least
two rotary
elements oriented on the leading end of the power transfer unit enabling
torque produced by
one of the at least two rotary elements to be counteracted by torque created
by another of the
at least two rotary elements; and an elongated member system having a
flexibility and
stiffness to be moved through the pipe, said elongated member system attached
to a trailing
end of the power transfer unit and providing said power transfer unit with
means for
activation.
In accordance with another aspect of the present invention there is provided a
pipe clearing
system comprising: a power transfer unit sized to be accepted within a pipe;
an elongated
member system having a flexibility and stiffness to be moved through the pipe,
said
elongated member system attached to a trailing end of the power transfer unit
and providing
said power transfer unit with means for activation; and at least two rotary
elements for
disturbing a clog in the pipe, the at least two rotary elements mounted on a
leading end of the
power transfer unit, said at least two rotary elements oriented on the leading
end of the power
transfer unit enabling torque produced by one of the at least two rotary
elements to be
counteracted by torque created by another of the at least two rotary elements.
2o BRIEF DESCRIPTION OF THE FIGURES
Figure 1 shows a system diagram of a pipe clearing system according to one
embodiment of
the present invention.
Figure 2 shows a system diagram of a pipe clearing system according to another
embodiment
of the present invention, wherein the power transfer units) is hydraulically
operated.
Figure 3 shows a side view of a pipe clearing device according to one
embodiment of the
present invention.
3o Figure 4 shows a side view of a power transfer unit with a streamlined
casing according to
7
CA 02472609 2004-06-28
MBM File No. 1263-103
one embodiment of the present invention.
Figure 5 shows a cross-sectional isometric view of a power transfer unit
containing four
hydraulic motors according to one embodiment of the present invention.
Figure 6A shows a cross-sectional side view of a worm screw according to one
embodiment
of the present invention.
Figure 6B shows a cross-sectional side view of a pair of mirror-image worm
screws
t o according to one embodiment of the present invention.
Figure 6C shows a cross-sectional side view of a pair of mirror-image worm
screws
according to another embodiment of the present invention.
Figure 6D shows a cross-sectional side view of a worm screw according to
another
embodiment of the present invention.
Figure 6E shows a cross-sectional side view of a worm screw according to a
further
embodiment of the present invention.
Figure 6F shows a cross-sectional side view of a worm screw according to
another
embodiment of the present invention.
Figure 6G shows a cross-sectional side view of a worm screw according to
another
embodiment of the present invention.
Figure 7A shows a front view of a configuration of four worm screws according
to one
embodiment of the present invention.
3o Figure 7B shows a front view of a configuration of four worm screws
according to another
embodiment of the present invention.
8
CA 02472609 2004-06-28
MBM File No. 1263-103
Figure 7C shows a front view of a configuration of four worm screws according
to a further
embodiment of the present invention.
Figure 8 shows a side view of a pipe clearing device with wire cutters
according to one
embodiment of the present invention.
Figure 9 shows a perspective view of a pipe clearing device with wire cutters
according to
one embodiment of the present invention.
to DETAILED DESCRIPTION OF THE INVENTION
Definitions
The term "coaxial tube" is used to define a type of tube where an inner tube
is sleeved inside
an outer tube, such that the inner tube provides an inner channel, and the
space between the
inner and outer tube provides an outer channel.
The term "motor" is used to define any form of actuating system which can
provide a means
for activating a device. For example the term motor can define a hydraulic,
pneumatic,
electrical or other form of actuating systems as would be known to a worker
skilled in the art.
2o The term "pipe" is used to define any type of device used to transfer a
fluid and can comprise
a sewer pipe, water distribution pipe, rectangular pipe, circular pipe or any
other type of pipe
as would be readily understood by a worker skilled in the art.
Unless defined otherwise, all technical and scientific terms used herein have
the same
meaning as commonly understood by one of ordinary skill in the art to which
this invention
belongs.
The present invention provides a device and system for cleaning, unclogging or
clearing a
pipe. The pipe clearing system comprises a "Power Transfer Unit"(PTU) sized to
be
3o accepted within a pipe which is interconnected to an elongated member
system having a
9
CA 02472609 2004-06-28
MBM File No. 1263-103
flexibility and stiffness to be moved through the pipe. This elongated member
system is
attached to the trailing end of the PTU and provides the PTU with power
thereby providing a
means for actuating said PTU. For example, in one embodiment of the present
invention, the
elongated member system contains hydraulic tubes which allow for the supply of
a hydraulic
fluid in order to drive one or more hydraulic motors inside the PTU. In
another embodiment
of the present invention, the elongated member system contains electrical
wires for supplying
electricity to one or more electrical motors inside the PTU. On the leading
end of the power
transfer unit are mounted at least two rotary elements for disturbing a clog
or obstruction in
the pipe. These rotary elements are oriented on the leading end of the power
transfer unit in
1o such a configuration as to enable torque generated by one of the rotary
elements to be
counteracted by the torque generated by another of the rotary elements thereby
reducing the
net torque acting on the device as a whole and transmitted to the elongated
member system.
In one embodiment of the present invention, the pipe clearing system comprises
two counter-
rotating rotary elements, such that the torque produced by a rotary element
rotating clockwise
t 5 is approximately equal to and opposite the torque produced by the rotary
element rotating
counter-clockwise, thereby reducing the rotation and twisting of the elongated
member
system associated with the device if for example, the rotary elements
encounter resistance
from an obstruction in the pipe or sewer.
2o The "power transfer unit"(PTU) converts power transmitted along the
elongated member
system, into rotational motion which, in turn, is transmitted to the rotary
elements. The PTU
may optionally include a casing or shield.
In one embodiment of the present invention, the PTU uses hydraulic motors to
rotate the
25 rotary elements. A closed hydraulic system within the elongated member
system can provide
tubes for carrying a hydraulic fluid to the PTU of the device to power the
rotary elements and
for carrying the fluid back from the PTU. Because the hydraulic system is a
closed system, it
can avoid releasing additional fluid into the pipe.
30 In another embodiment of the present invention, the PTU may produce
rotational motion by
means of pneumatic, electrical, or other motors known to a worker skilled in
the art.
CA 02472609 2004-06-28
MBM File No. 1263-103
In one embodiment of the present invention, a power transfer unit has
rotatable attachment
sites, to which a user may attach appropriate rotary elements selected based
on the situation
at hand. The rotatable attachment sites provide a means for interchangeability
of these rotary
elements. The rotary elements can perform functions including for example,
cutting,
mulching, boring and clearing a pipe blockage. Additionally, certain rotary
elements can
assist the user with propelling the clearing device in a forward and backward
direction
through the pipe or sewer.
In another embodiment of the present invention, the pipe clearing device has
rotary elements
that are permanently connected to the PTU. The user may have several different
PTUs each
having a different set of rotary elements on the leading end thereof.
Figure 1 shows a system diagram of one embodiment of the pipe clearing system
according
t 5 to the present invention. As illustrated, a power source 150 is attached
to the PTU by a main
cable 170, which forms a portion of the elongated member system. Structural
reinforcement
of the cable may also help to neutralize torque on the PTU and the cable and
can aid in
preventing twisting of the cable. The main cable is attached to a PTU 180,
which is inserted
into a pipe 190. The PTU 180 has two or more rotary elements 182 connected
thereto.
In one embodiment of the present invention, the rotary elements are connected
to the PTU
via rotatable attachment sites 186. The PTU converts power, transmitted to it
through the
main cable or elongated member system, into mechanical rotation that is
transmitted to the
rotary elements 182, for example, via the rotatable attachment sites to which
said rotary
elements are connected. The rotatable attachment sites allow the user to
select and attach
rotary elements depending on the requirements of a specific task. For example,
the rotatable
attachment sites may allow for the attachment of cutting heads which can be
used to cut into
and dislodge the blockage 140.
3o Figure 2 shows a system diagram according to an embodiment of the present
invention,
wherein power is transmitted to the PTU hydraulically. A hydraulic pump 130 is
driven by a
11
CA 02472609 2004-06-28
MBM File No. 1263-103
motor 110 using a drive shaft 120, belt or other means. The pump motor 110
may, for
example, be an electrical motor, drawing current from a outlet, battery,
generator or other
electrical power source as would be known to a person skilled in the art.
Alternatively, the
pump motor may be a fuel-powered motor or some other motor such as would be
known to a
person skilled in the art. The pump motor has a switch enabling the operator
to turn the
motor on and off. Controls may be provided to allow the operator to vary the
speed of the
motor and therefore the speed of the hydraulic pump. The hydraulic pump is
connected to a
hydraulic switch 140, wherein the hydraulic switch has two positions
corresponding to the
two different flow directions of the fluid. The hydraulic switch may also
provide a stop
1o position. As well, the system can have a safety relief pressure bypass, for
example located in
the pump or switch, to prevent damage from occurring due to excessive
pressure. The output
of the hydraulic switch is attached to the PTU by a main cable 170 which
provides two
hydraulic channels 172 and 174. These channels may be provided by coaxial
tubes or by
adjacently placed tubes. In one embodiment of the present invention, the cable
is reinforced
structurally, for example, by a flexible wire 176, in order to prevent
excessive bending or
kinking of the cable. Structural reinforcement of the cable may also help to
neutralize torque
on the pipe clearing device and to prevent twisting thereof.
In one embodiment of the present invention, and as shown in Figure 2, the main
cable is
2o attached to a PTU 180, which is inserted into a pipe 190. The PTU 180 has
two or more
rotary elements 182. In one embodiment of the present invention, the rotary
elements are
connected to the PTU via rotatable attachment sites 186. The PTU converts the
flow of
hydraulic fluid into mechanical rotation which is transmitted to the rotary
elements 182, for
example, by the rotatable attachment sites to which said rotary elements are
connected. The
rotatable attachment sites allow the user to select and attach rotary elements
depending on the
requirements of a specific task. For example, the rotatable attachment sites
may allow for the
attachment of cutting heads which can be used to cut into and dislodge the
blockage 140.
In one embodiment of the present invention, the pipe clearing device can be
used, for
3o example, to clear obstructions in building sewers, by accessing them, for
example, via a 3-
inch to 4-inch clean-out connection between a main building and the city sewer
as would be
12
CA 02472609 2004-06-28
MBM File No. 1263-103
readily understood by a worker skilled in the art.
POWER TRANSFER UNIT
The power transfer unit (PTU) converts power transmitted elongated member
system into
rotational motion which, in turn, is transmitted to the rotary elements. In
one embodiment of
the present invention, the rotational motion is transmitted from the PTU to
the rotary
elements via rotatable attachment sites. In one embodiment of the present
invention, the
PTU contains one or more motors to produce rotational motion. Said motors may
include,
for example, pneumatic, electrical, hydraulic or other motors. The rotational
motion of a
1o motor is transmitted to one or more rotary elements via rotatable
attachment sites either
directly by means of rotating shafts, or indirectly via gears, drive belts, or
other means such
as would be known to a worker skilled in the art.
Figure 3 shows an embodiment of the PTU. The PTU 210 has, on its trailing end,
one or
more connectors 220 for attaching to the main cable 170 of the elongated
member system.
On the leading end of the PTU are rotatable attachment sites 186 and 188 to
which one can
attach rotary elements 182 and 184.
The PTU may be surrounded by a casing or shield. Said casing may, for example,
be
2o protective. In one embodiment of the present invention, the PTU is
surrounded by a
hydrodynamically shaped casing, which facilitates the movement of the device
into and out
of the pipe. Figure 4 shows an embodiment of the power transfer unit having a
shaped casing
210. The device has, on its trailing end, a connector or set of connectors 220
for attaching to
the elongated member system. On the leading end of the power transfer unit are
rotatable
attachment sites 186 and 188 to which one can attach rotary elements.
In one embodiment of the present invention, the PTU comprises centering guides
for
centering the power transfer unit within the pipe.
3o In one embodiment of the present invention, the PTU is hydraulic. In one
embodiment of the
present invention, the hydraulic PTU contains 1 or more hydraulic motors and a
casing. In
13
CA 02472609 2004-06-28
MBM File No. 1263-103
one embodiment of the present invention, the power transfer unit contains 4
hydraulic motors
connected serially or in parallel, for example. For example, in one embodiment
of the
present invention, and with reference to Figure 5, the motors are connected in
serial, such
that the fluid inlet 510 of the PTU leads to the inlet of the first hydraulic
motor 520 while the
fluid outlet of the first hydraulic motor 520 is connected to the inlet of the
second hydraulic
motor 530, which in turn has its outlet connected to the inlet of the third
hydraulic motor 540,
which in turn has its outlet connected to the inlet of the fourth hydraulic
motor 550, which in
turn has its outlet leading to the outlet 560 of the PTU. To provide balanced
torque, two of
the hydraulic motors rotate in one direction, while the other two rotate in
the opposite
1o direction. For example, the hydraulic motors 520 and 530 can rotate in one
direction while
motors 540 and 550 rotate in the opposite direction. Other patterns of counter-
rotating
motors would be readily understood by a worker skilled in the art. Each
hydraulic motor has
a rotating shaft, at the end of which is a rotatable attachment site. It will
readily understood
by a worker skilled in the art that a smaller or greater number of serially-
connected hydraulic
motors may be used. A parallel connection configuration of multiple motors in
the power
transfer unit would additionally be readily understood by a worker skilled in
the art.
In another embodiment of the present invention, the pipe clearing system may
comprise more
than one hydraulic circuit, such that the elongated member system comprises
more than one
2o pair of incoming and outgoing hydraulic channels. Such a configuration
would allow for the
independent control of the motor or motors corresponding to each hydraulic
circuit.
In another embodiment of the present invention, one or more hydraulic motors
are used, and
the rotational motion is transmitted to two or more rotatable attachment
sites. The rotational
motion is transmitted from the hydraulic motors to the rotatable attachment
sites by means
such as, for example, shafts, gears, drive belts and other means such as would
be known to a
worker skilled in the art.
Suitable hydraulic motors include, for example, hydraulic motors using an
impeller with a
sealed bearing assembly, as well as other hydraulic motors such as would be
known to a
worker skilled in the art. It will be understood by a worker skilled in the
art that other types
14
CA 02472609 2004-06-28
MBM File No. 1263-l03
of hydraulic motors and impeller assemblies may be substituted.
In another embodiment of the present invention, pneumatic means are used to
actuate the
power transfer unit. The elongated member system in this embodiment can
comprise one or
more pairs of pneumatic channels for incoming and outgoing gas.
In another embodiment of the present invention, electrical means are used to
actuate the
power transfer unit. In this embodiment the elongated member system comprises
conducting
wires providing power to one or more electrical motors in the PTU. In one
embodiment of
to the present invention, more than one electrical circuit is used, enabling
independent control
of the motors associated with each circuit. In another embodiment of the
present invention,
wires are used to transmit control signals to circuits inside the device for
controlling the
motors such as would be understood by a worker skilled in the art.
I5 COUNTER-ROTATING ROTARY ELEMENTS
The PTU is connected to two or more counter-rotating rotary elements, such
that the torque
produced by clockwise-rotating rotary elements is approximately equal the
torque produced
by counter-clockwise rotating rotary elements. As such, little or no net
torque is applied to
the PTU or to the elongated member system connected thereto.
For example, torque on the elongated member system leading to the PTU may be
caused by a
rotary element that encounters resistance from an obstruction inside the pipe.
For example, if
a worm screw used to cut through an obstruction, the interaction of the
rotating screw with
the resistant obstruction would apply torque on the PTU. Such torque could
cause the PTU
to rotate in the opposite direction. By having two matched worm screws
rotating in opposite
directions, the overall torque acting on the pipe clearing device can be
reduced.
Torque can also result from a rotary element's interaction with fluid inside
the pipe or with
the sides of the pipe. Net torque due to such interaction can also be reduced
by the balanced
counter-rotation of rotary elements.
CA 02472609 2004-06-28
MBM File No. 1263-103
One advantage to minimizing the torque applied to the PTU and elongated member
system is
that torque created by the rotary elements will typically not cause the PTU to
spin. As such,
the PTU can provide an adequately stable mounting point for a camera enabling
the operator
of the pipe clearing system to examine the inside of the pipe. Such a camera
can be powered,
for example, by a wire running along the elongated member system, to a battery
or to some
other energy storage device, for example. The video signal can be transmitted,
for example,
using a wire or wirelessly by means of a radio signal. Various means of
powering small
cameras and transmitting picture signals are known in the art. The use of
counter-rotating
rotary elements can also help reduce vibration of the pipe clearing device,
thereby allowing a
1o mounted camera to function more effectively and provide a clearer or more
stable image for
example.
Another advantage to minimizing net torque is that it prevents the elongated
member from
twisting excessively, thereby making the pipe clearing device easier to
manipulate and can
reduce damage to the elongated member.
In one embodiment of the present invention, the overall torque on the PTU is
minimized by
having an even number of rotary elements tools, where every clockwise-rotating
rotary
element is paired with a matching but counterclockwise-rotating rotary
element, such that
2o there is little or no net torque applied to the PTU or to the elongated
member system. Paired
rotary elements may be mirror images of each other, for example.
Figure 6B shows a pair of worm screws in one embodiment of the present
invention 610, 620
that are mirror images of each other. Figure 6C shows a pair of mirror image
worm screws
630, 640 in another embodiment of the present invention. Figure 7A shows a
front view of
four worm screws according to yet another embodiment of the present invention,
wherein
worm screws 710, 714 are counter-clockwise rotating, while worm screws 712,
716 are
clockwise rotating.
3o In another embodiment of the present invention, every clockwise-rotating
rotary element
need not be paired to a matching counterclockwise-rotating rotary element.
Rather, the
16
CA 02472609 2004-06-28
MBM File No. 1263-103
rotary elements are selected and positioned in such a way that the total
torque produced by all
clockwise-rotating elements essentially balances out the total torque produced
by all
counterclockwise-rotating elements so that there is little or no net torque on
the PTU and
elongated member system. Since torque is calculated by multiplying force by
radius, rotary
elements may be selected having appropriate radii such that the net torque on
the PTU and
elongated member system is reduced. If different rotary element types are
combined, the
radii can be adjusted to reflect the different force acting on different types
of rotary elements.
Since rotary elements may in one embodiment, be easily interchangeable, the
user can easily
replace rotary elements if excessive torquing is experienced by the PTU and
elongated
1 o member system. For example, if excessive torquing indicates that there is
too much torque
produced by clockwise-rotating elements, the user may exchange a counter-
clockwise
rotating element with one having a larger radius in order to further
counteract the torque.
Alternatively, the user may replace a clockwise-rotating element with one
having a smaller
radius, for example, to reduce the torque produced thereby, for example.
ROTARY ELEMENTS
The PTU is connected to two or more rotary elements. In one embodiment of the
present
invention, and with reference to Figure 3, the PTU has two or more rotatable
attachment sites
186 where a variety of rotary elements can be connected. For example, the
rotatable
2o attachment sites are driven by rotating shafts. A variety of attachable
rotary elements of
various shapes and designs can thus be used. The rotary elements present on
the PTU may
include, for example, cutters, mulchers, strimmers, worm screws, worm gears,
or propellers.
The attachment sites may comprise for example, tool chuck assemblies or other
attachment
means such as would be known to a worker skilled in the art.
Worm-screws
In one embodiment of the present invention, the PTU is connected to rotary
elements such as,
for example, worm gears, worm screws, or helically wound propellers or helical
gears. Each
rotary element may comprise, for example, one or more threads or gear blades
or a helically-
3o wound knife edge fan, or propeller-type worm gears, and have a particular
pitch, size, depth
and length.
17
CA 02472609 2004-06-28
MBM File No. 1263-103
Figures 6D, 6E, 6F and 6G show worm screws, according to an embodiment of the
present
invention, having various pitch, size, depth and length.
Each rotary element may optionally be pointed at the leading edge, providing a
cutter tip.
Worm screws can have sharp-edged threads that cut as the worm screws rotate.
In one
embodiment of the present invention, and with reference to Figure 6A, the gear
threads are
smaller in diameter at the foremost tip 602 of the worm screw and become
progressively
larger towards the back, up to a maximum size 604 which allows for a
sufficient specified
clearance between the worm gear size and pipe diameter. For example, for
certain
circumstances, 3-inch diameter worm gears could be selected for use in 6-inch
diameter pipes
to allow for 3 inches of clearance. Also, in another embodiment of the present
invention, the
gear thread may be smallest in diameter at the foremost tip, gradually
increasing in diameter
up to a maximum diameter, and then gradually reduce in diameter as it nears
the rotatable
t 5 attachment site. Such a design helps to facilitate forward and backward
movement of the
pipe clearing device within the pipe by providing a hole-enlarging capability
in a forward
direction when in a forward mode of operation as well as in a backward
direction when the
pipe clearing device is set in reverse mode of operation.
20 In one embodiment of the present invention, the rotation of the worm screws
can propel the
PTU forwards or backwards along the interior walls of the pipe as the gears
screw or worm
against the sides of the pipe providing thrust for self propelled locomotion.
The direction of
propulsion can be determined by the direction of the rotation of rotary
elements and the
helical winding of the tool. By reversing the direction of rotation of the
rotary elements, the
25 direction of propulsion can be reversed.
In an embodiment of the present invention, a worm screw or worm gear
configuration can
provide propulsion inside a backed up sewer full of fluid and sewage by
displacing the fluid
in one direction as it rotates, thereby generating thrust.
In an embodiment of the present invention, and with reference to Figure 7B,
adjacent worm
18
CA 02472609 2004-06-28
MBM File No. 1263-103
gears or worm screws are close to each other such that their threads are
meshed or geared
with each other. For example there can be a meshing or gearing of the counter-
rotating
threads of left-hand and right-hand threaded screws. The meshing or gearing of
counter
rotating threads, gears, blades, screws can provide a cutting and/or mulching
action to clear
obstructions in the sewer while applying little or no net torque to the pipe
clearing device.
For example, in one embodiment of the present invention, and with reference to
figure 7B,
worm screws 720 and 722 are intermeshed; worm screws 722 and 724 are
intermeshed;
worm screws 724 and 726 are intermeshed; worm screws 726 and 720 are
intermeshed.
t o In an embodiment of the present invention, one or more worm screw gear
blades provide
thrust against the interior walls of the pipe as the edges of the gear blades
rotate, screw, or
worm at for example user-controllable speeds for locomotion. The screws can be
designed to
drill and mulch obstructions to clear blocked building drains and sewers. For
example, the
worm gear configuration can propel itself towards the blockage in a full sewer
pipe. Once
~ 5 the site of blockage is reached, the screw worm gear blades can drill and
mulch. The rotation
of the worm gears can help propel the PTU through the obstructed area while
the gears mulch
debris. Thus, for example, by drilling and mulching through the obstruction,
gears can
unblock the sewer, thereby allowing the backed-up fluids to drain away and
clear away the
debris.
In an embodiment of the present invention, rotary elements are designed to
pass through
common sewer pipe structures such as, for example, 3-inch clean-out openings,
45-degree
and 90-degree elbows, 4-inch Tee Wyes and sanitary drainage fittings.
A worm screw or gear may be composed of materials such as, for example, steel,
stainless
steel, brass, aluminum, metallic alloys, plastic, composites, fiberglass or
other suitable
materials as would be readily understood. Edge covers of composites can be
used for gear
blades which can provide protection for the interior walls of the pipe for
example during
rotation of these type of rotary elements. The worm screw center shaft can
terminate at a
length short enough to enable the PTU to pass through bends in the pipe, for
example.
19
CA 02472609 2004-06-28
MBM File No. J263-103
In one embodiment of the present invention, variations of worm screw design
can allow a
configuration of two, four or more worm gear screws to produce a boring
diameter that
oscillates in size as the worm screws rotate. Said variations of worm screw
designs include
offset helical screws wherein the radius from the axis of rotation fluctuates
along the worm
screw thread. Offset helical blades can allow for the cutting diameter of the
worm screw to
oscillate in size as the screws rotate.
In one embodiment of the present invention, and with reference to Figure 7C, a
configuration
of offset worm screws 730, 732, 734, 736 produces an oscillating boring
diameter. Said
1o configuration of worm screws can have the capability of boring, for
example, a 4-inch
diameter hole while still retaining the ability to be threaded through, for
example, a 3-inch
diameter building clean-out sewer access point. For example, the user of the
pipe clearing
device may turn off the power to the PTU, or lower the speed of the rotary
elements to push
the PTU through a narrow hole, and then turn on or increase the speed of the
rotary elements
when the PTU encounters the obstruction that is to be dislodged.
Wire Cutter tool
In one embodiment of the present invention, the PTU is equipped with a rotary
element that
is a wire cutter tool. A wire cutter tool has one or more spinning wires
capable of disturbing
blockages or debris with which they come into contact. One or more wire cutter
tools can be
attached to corresponding rotatable attachment sites of the PTU. Two or more
wire cutter
attachments can rotate counter to each other in order to minimize net torque
on the pipe
clearing device as a whole.
In another embodiment of the present invention, and with reference to Figure
8, two wire-
cutter tools are arranged such that a set of rotating wires 810 is located
further forward at the
leading end of the PTU, and another set or wires 820 is located further to the
trailing end.
The two wire-cutter tools rotate around the same shaft but in opposite
directions. This
configuration allows a longer length of wire to be used while reducing the
interference
between the wires. Centering guides 830 can be attached to the PTU to help
center it inside
the pipe. The PTU can have a connector or set of connectors 220 for connecting
it to the
CA 02472609 2004-06-28
MBM File No. 1263-103
main cable 170 of the elongated member system. In one embodiment of the
present
invention, the foremost wire-cutter tool is connected to an inner shaft
rotating in one
direction, while the subsequent wire-cutter tool is connected to an outer
shaft rotating in the
opposite direction. In another embodiment of the present invention, the
foremost wire-cutter
tool is actuated by one motor, while the subsequent wire-cutter tool is
actuated by a different
motor. In yet another embodiment of the present invention, four sets of wire-
cutter tools are
actuated by four separate motors. It will be readily understood by a worker
skilled in the art
that other configurations of wire cutter tools are possible.
to Figure 9 shows the PTU with two sets of wire cutters in one embodiment of
the present
invention. The PTU has an anterior set of wire cutters 810 and an ulterior set
of wire cutters
820. The PTU can have centering guides 830.
In another embodiment of the present invention, the attached rotary elements
can include, for
example, disks, spools or rings from which cutting wires extend, or other
rotating pipe
clearing implements such would known to a worker skilled in the art.
ELONGATED MEMBER SYSTEM
The trailing end of the pipe clearing device is connected by an elongated
member system or
2o apparatus that provides power to the PTU. During operation of the pipe
clearing device, a
portion of the elongated member system is within the pipe being cleared and a
portion of the
elongated member system is external to this pipe. The portion of the elongated
member
system outside the pipe can include, for example, switches for controlling the
operation of
the pipe clearing device. The apparatus outside the pipe also includes
equipment for
actuating the PTU. Depending on whether the device is actuated by hydraulic,
pneumatic, or
electrical means, the elongated member system may comprise hydraulic or
pneumatic
channels, or conductive wires.
Hydraulic Elongated Member System
In one embodiment of the present invention, and with reference to Figure 2,
the PTU 180 is
hydraulically actuated. As such, the PTU contains hydraulic motors. The
elongated member
21
CA 02472609 2004-06-28
MBM File No. 1263-103
system outside of the pipe includes a hydraulic pump 130 connected to the main
cable 170 of
the elongated member system leading to the PTU 180 which is placed inside the
pipe. In one
embodiment of the present invention, the hydraulic pump is, for example, a
portable,
compact, pump with a reservoir, and is suitable in terms of size, weight and
power. The
hydraulic pump can comprise controls to vary directional flow of hydraulic
fluid from the
pump to one or more hydraulic power transfer units to allow for forward and
reverse rotation
of rotary element operations. In one embodiment of the present invention, the
hydraulic
pump utilizes a bio-degradable hydraulic fluid such as for example vegetable
oil or other
suitable fluid. In one embodiment of the present invention, the pump is
powered by an
1o electrical motor. In another embodiment of the present invention, the
hydraulic pump and
motor are small, compact, lightweight and portable.
In one embodiment of the present invention, and with reference to Figure 2,
the electric
motor 110 is, for example, a standard, alternating current, 120 volt unit
which can be plugged
into a power receptacle, for example a household power receptacle, or another
power
receptacle. In another embodiment of the present invention, the pump can draw
power from,
for example, a generator, a battery, or any other source of electrical energy.
The electric
motor is coupled to the hydraulic pump to provide hydraulic pressure and flow
of the
hydraulic fluid. The electric motor can be sized to meet desired power/weight
specifications.
2o The self contained hydraulic system can be designed to not introduce any
extra fluid into
incapacitated or blocked pipes or sewers that may be already full of water The
use of a
closed hydraulic system can minimize extra fluid from being released into the
pipe, thereby
reducing the chance of sewage overflow.
In one embodiment of the present invention, the main cable of the elongated
member system
comprises a hydraulic tube that can be loosely coiled or in a drum. The
hydraulic tubing for
conveying fluid power from the hydraulic pump to the hydraulic PTU comprises
two or more
hydraulic separate chambers. In an embodiment of the present invention, the
lengths of the
hydraulic tubes can vary to up to approximately 100 feet, for example.
In one embodiment of the present invention, and with reference to Figure 2,
the hydraulic
22
CA 02472609 2004-06-28
MBM File No. 1263-103
tubing 172 allows hydraulic fluid to pass from the pump 130 to the hydraulic
PTU 180 and
then return to the hydraulic pump reservoir. Both ends of the hydraulic tube
feed line 172
and return line 174 assembly may terminate with quick-connector adapters to
attach to the
pump assembly 130 at one end, and to the PTU 180 at the other end.
In one embodiment of the present invention, the hydraulic tubes are coaxial,
such that one
channel is sleeved inside the other. The inner tube provides a central fluid
channel, while the
space between the inner and outer tubes serves as an outer fluid channel.
Accordingly, the
connector with the hydraulic PTU would have an inner port sleeved inside an
outer port.
to
In an embodiment of the present invention, the tubes may be made stiffer or
more rigid using,
for example, wires or rods having a desired degree of stiffness and
flexibility. A certain
degree of stiffness or rigidity may make the tube easier to direct into the
pipe to be cleared.
Furthermore, stiffness can prevent the tube from bending sharply and cutting
off the flow of
hydraulic fluid through said tube. In one embodiment of the present invention,
the tube may
be reinforced with, for example, a rod stiff enough to prevent kinks and sharp
bending, but
flexible enough to be threaded through the bends present in the pipe that is
to be cleared.
Optionally, the material from which the tube is fabricated can have an
inherent stiffness
based on the pressure rating of the tube in order to appropriately actuate the
one or more
2o hydraulic motors in a PTU.
Pneumatic Elongated Member System
In another embodiment of the present invention, the PTU may be pneumatically
actuated. In
this embodiment the elongated system comprises pneumatic pumps for generation
of the
desired pressure for activation of the PTU. Outside the pipe, a pneumatic
pump, powered,
for example, by electricity, provides pneumatic pressure to the pneumatic PTU.
Electrical Elongated Tubular Member System
In yet another embodiment of the present invention, the PTU is actuated by one
or several
3o electrical motors. In this embodiment the elongated system contains
conductive wires. The
main cable leads from the trailing end of the pipe clearing device to a power
supply located
23
CA 02472609 2004-06-28
MBM File No. 1263-703
outside the pipe. Switches can allow the user to turn the motor on and off. In
one
embodiment of the present invention, switches allow the user to reverse the
direction of the
motor or motors, and/or vary their speed.
The invention being thus described, it will be obvious that the same may be
varied in many
ways. Such variations are not to be regarded as a departure from the spirit
and scope of the
invention, and all such modifications as would be obvious to one skilled in
the art are
intended to be included within the scope of the following claims.
24
