Note: Descriptions are shown in the official language in which they were submitted.
CA 02709243 2010-04-30
Title
Hose Occluding Pulley Block for Wave-Powered, Reciprocating Hose Peristaltic
Pumps
Technical Field
This invention relates generally to wave-powered pumping devices. More
particularly,
it relates to an improved hose occluding pulley block which can be employed as
a
component of a wave-powered, reciprocating hose peristaltic pump such as that
described
in my patent application No. PCT/CA2009/00649, Wave-Powered, Reciprocating
Hose
Peristaltic Pump.
Background Information and Prior Art
Driven by a number of factors including increasing demand, the dwindling of
low-cost
reserves and increasing global conflict, energy costs have risen dramatically
in recent
years. Predictions are that these costs will continue to escalate over time as
reserves are
depleted. At the same time, there is growing alarm in both the scientific
community and the
general population about the effects of global warming and its relationship to
the burning
of fossil fuels, our primary source of energy.
As a result, there is now international consensus that the development and
widespread
deployment of clean, renewable and sustainable energy technologies must be
supported
CA 02709243 2010-04-30
3
by industry and governments at all levels and that the transition to these
technologies
must occur with all expediency.
This shift is now well underway and is expected to gain momentum. This is
evidenced by
the continuing rapid growth of wind and photovoltaic installations in a
growing number of
countries worldwide. More recently, the focus has been expanded to involve new
opportunities, with investment in research and development in ocean energy
conversion
being particularly high. Beyond the obvious environmental benefits, ocean wave
and swell
energy is of great interest because of its much higher density and consistency
than wind
and solar energies and it is widely distributed.
The impact of this transition has been accompanied by a high profile debate
that has
become increasingly geopolitical in nature as particularly evidenced by
ongoing and
evolving reaction to the Kyoto Accord. Currently, the greatest single issue
expressed by
the so-called holdout nations relates to a requirement for much greater use of
cleaner and
more efficient energy technologies by the underdeveloped and developing
nations, many
with huge and expanding populations.
At the same time, there is increasing recognition of the need for and use of
what has been
termed "appropriate technology" if these efforts are to be successful.
Usually, the term has
been described as synonymous with, simple, low-cost, easily taught and
serviced and,
more often than not, small in size and capacity by developed nation standards;
in effect,
often requiring a paradigm shift in terms of thinking and design.
The demand for these new technologies is not limited to these markets however.
There is
also demand from a growing segment of the population in highly developed
nations for
cost effective alternative energy technologies that can be used to provide for
small
community, organizational and even individual needs in addition to the more
common,
centralized installations requiring a distribution grid infrastructure.
In terms of prior art developed by others, most research and development
continues to
focus on very large utility scale apparatus, the smallest of which can cost in
the millions of
dollars. Unfortunately, most of these designs do not scale down well nor are
they suitable
for use in many regions where need is high but both wave climates and budgets
are
CA 02709243 2010-04-30
4
modest. In those cases, related costs also add tremendously to overall versus
acquisition
costs for these apparatus. In particular, delivery and handling, installation
and start-up
and, where the devices are located offshore or are fully sub-surface, routine
maintenance
costs. In addition, because these apparatus typically incorporate a
significant number of
custom and highly specialized components rather than readily available,
competitively
priced parts and service items, the cost benefits often associated with
economies of scale
and volume are limited. None are ideally suited for rapid deployment during
times of crisis
such as natural disaster relief.
To a lesser degree, smaller, more flexible prior art apparatus that can be
deployed in
arrays when higher output levels are needed have also been proposed with some
now
under development and testing. Although these devices have made some progress
towards overcoming the deficiencies outlined above, they too exhibit certain
limitations.
As a result, I conceived and developed the device described in my patent
application No.
PCT/CA2009/00649, Wave-Powered, Reciprocating Hose Peristaltic Pump to address
these deficiencies thereby providing an improved, more practical apparatus.
The present
invention relates to several novel improvements to the occluding pulley block
assembly
described therein. More specifically, these improvements have been conceived
and
designed to address potential issues and/or deficiencies related to; the more
timely and
more fully re-opening of the peristaltic hose following occlusion, maintaining
occlusion in
spite of changes and variation in wall thickness of the peristaltic hose,
whether due to a
pre-existing condition as a result of changes due to gradual fouling and
sediment buildup
on the surface of the peristaltic hose, and preventing damage to the apparatus
due to
sudden pressure spikes or surges that could occur as a result of rapidly
rising waves, as
can occur during storms as well as other new features. Therefore, related
prior art is
referred to by way of that cited in the written opinion of the International
Searching
Authority in my earlier patent application; PCT/CA2009/00649, Wave-Powered,
Reciprocating Hose Peristaltic Pump, Vowles, Gerald J. International filing
date 13 May
2009 (13-05-2009).
CA 02709243 2010-04-30
List of Figures
Fig. 1 shows a side view of how one embodiment of the present invention, that
being a
hose occluding pulley block is incorporated into a wave-powered, reciprocating
hose
peristaltic pump.
Fig. 2 shows a side view of an open-body, hose occluding pulley block
incorporating a
means by which a peristaltic hose operating within it is caused to return to
its normally
round, internally open state following occlusion.
Fig. 3 shows a side view of the device shown in Fig.2 with the addition of
replaceable
peristaltic hose cleaning means, manual occlusion gap adjustment means and a
combined
means of increasing the width of the occlusion point and self-adjusting for
minor variations
in thickness of the peristaltic hose.
Fig. 4 shows a side view of a device similar to that shown in Fig.3 wherein
alternate
means are provided for manual as well as minor self-adjustment of the
occlusion gap,
as well as means for relieving spikes in fluid pressure within the pump are
incorporated.
Fig. 4a shows a side view of a variation of the alternate means for manual as
well as
minor self-adjustment of the occlusion gap and the means for relieving spikes
in fluid
pressure within the pump are incorporated taught in Fig. 4.
Fig. 5 shows a side view of an open-body, hose-occluding pulley block wherein
occlusion
of the peristaltic hose occurs as a result of the pulley about which it
rotates being pulled up
against one or more occlusion rollers rather than by one of more occlusion
rollers being
forced up against the peristaltic hose as shown in Fig's. 2 and 3. A means is
also shown
for limiting the amount of compression so caused.
Fig. 6 shows a side view of a device similar in function to that taught in
Fig. 5 but with an
alternative means of limiting compression of of the peristaltic hose.
CA 02709243 2010-04-30
6
Fig. 7 shows a side view of a device equivalent to that taught in Fig. 6
except that the
pulley about which the peristaltic hose rotates is not physically attached to
the device.
Fig. 8 shows a side view of a device functionally equivalent to that shown in
Fig. 2 but with
a housing similar in construction to a conventional, rope style fiddle block,
except that an
occluding roller rather than concave faced sheave is employed and a discrete,
peristaltic
hose occlusion opening means is attached.
Fig. 8a shows a side view of the occluding roller and peristaltic hose
occlusion opener
referred to in Fig. 8.
Fig. 9 shows an external side view cif a device that is functionally
equivalent to that
shown in Fig. 8 but employing what is commonly referred to as a snatch block
style
housing rather than the fiddle block style shown in Fig. 8.
Summary of the Invention
The invention taught in the following description is intended for use as a
component of a
wave-powered, reciprocating hose peristaltic pump typically operating in any
body of fluid
upon which surface waves may be propagated, usually by the movement of a
secondary
fluid across the surface of the first or primary fluid. However, for this
class of apparatus,
the primary fluid is typically a body of water such as an ocean, sea or lake
upon which
waves are propagated when a secondary fluid, which is typically wind, blows
across it.
Therefore, for the sake of clarity, this description will use the term "water"
to represent any
primary fluid and the term "wind" to represent any secondary fluid in this
context. This
pump is capable of delivering a flow of pressurized fluid to power one or more
driven
devices or processes such as but not limited to desalinators, electricity
generators,
hydraulic motors and hydrogen fuel generators. Again, for the sake of clarity,
the
pressurized fluid in this case would be water, typically being drawn from the
same body of
water in which the device is installed.
More specifically, the invention taught in the following description provides
a number of
improvements upon the compression pulley block taught in my earlier patent
application
PCT/CA2009/00649, Wave-Powered, Reciprocating Hose Peristaltic Pump, that
being a
CA 02709243 2010-04-30
7
pulley block capable of compressing a peristaltic hose drawn through it,
thereby causing a
temporary occlusion of the peristaltic hose at that point where it is in
contact with one or a
combination of freely rotating pulleys and compression rollers. The following
objectives
provide an overview of these new and novel improvements.
A first objective of this invention is to provide a means by which a
peristaltic hose is
returned to it's normally round, internally open condition upon passing the
point of
occlusion, thereby increasing the pumping efficiency and effectiveness of the
hose as well
as increasing the range of hose types and constructions that may be used as
components
of the apparatus.
A second objective of this invention is to provide a means by which the width
of the
occlusion is increased, thereby offering the ability to maintain a seal at the
point of
occlusion should irregularities be present in the hose's thickness, shape,
inner wall
smoothness or other associated variations, as well as increasing the pumped
fluid
pressure the seal is capable of producing and holding.
A third objective of this invention is to provide a means by which the
apparatus can self-
adjust the occlusion causing gap between the pulley and the compression
roller(s) in
those embodiments where one or more compression rollers are incorporated; this
in order
to adapt to hose construction and durometer variance, time and usage related
increases
or reductions in thickness and other similar factors involving variation in
thickness of the
walls and/or diameter of the peristaltic hose.
A fourth objective of this invention is to provide a means by which the
apparatus allows for
the opening or widening and subsequent return to normal of the occlusion
causing gap in
response to and, therefore, as a means of relieving excessive buildup, spikes
or surges in
pressure within the peristaltic hose. As such, this feature could also be used
to provide
basic pressure regulation.
A fifth objective of this invention is to provide the means by which the
occluding pulley
block can function effectively for longer periods of time without the cleaning
and
maintenance required as a result of buildup due to biological and non-
biological fouling.
CA 02709243 2010-04-30
8
A sixth objective of this invention is to provide convenient means by which
the
compression roller(s) for those embodiments incorporating that feature, may be
pressed
against the wall of the peristaltic hose during setup with enough force to
ensure proper
occlusion and to adjust and hold that force as needed during the setup.
A seventh objective of this invention is to provide the means by which the
premature
failure of a hose or other flexible member due largely to the uneven length of
their inner
and outer walls as they bend about a pulley can be reduced or eliminated.
An eighth objective of this invention is to provide the means by which the
pulley block and/
or peristaltic hose assembly can be more easily replaced in-situ.
A ninth objective of this invention is to provide the means by which the force
required to
cause occlusion of the peristaltic hose when using compression rollers is
provided by the
apparatus itself rather than by an external force.
Accordingly, the apparatus described herein provides the means by which these
objectives may be accomplished, as shall become apparent in the detailed
description that
follows.
Detailed Description of the Invention
Referring now to the drawings, the apparatus shown in Fig. 1 is representative
of a typical
wave-powered, peristaltic hose pump incorporating a peristaltic hose occluding
pulley
block, the latter being the focus of the present invention. In that regard, it
is noted that with
the exception of the novel improvements attributed to the present invention as
shall be
taught in Fig's 2 to 9, the general operating principles of a hose occluding
pulley block
operating as a component of a wave-powered peristaltic pump have previously
been
taught in my now published patent application No. PCT/CA2009/00649, Wave-
Powered,
Reciprocating Hose Peristaltic Pump, the description of which may be referred
to in the
event that the reader of this description wishes to further understand the
workings of the
present invention in the context of the larger apparatus. This is taken into
account in the
descriptions associated with Fig's 2 to 9 that follow, which are the focus of
the present
invention rather than that shown in Fig. 1 which is presented only for
improved clarity in
CA 02709243 2010-04-30
9
showing how the novel features of the present invention as taught in Fig's 2
to 9 share
the common purpose of being an integral component of such larger apparatus' as
that
shown and described in Fig. 1.
The apparatus shown in Fig. 1 can generally be described as follows: A wave-
powered,
reciprocating hose peristaltic pump installed in a body of water wherein a
peristaltic hose
assembly 1 is drawn back and forth through a hose occluding pulley block
assembly 2 by
opposing surface and sub-surface buoyant members or floats 3 and 4 reacting to
undulating wave action on the surface 5 of that body of water. This causes a
matched,
reciprocating inflow and outflow of water into and out of the peristaltic hose
assembly 1 as
it alternately lengthens and shortens on either side of a point where it is
temporarily
occluded within the relatively immoveable pulley block assembly 2. This
repeating cycle
occurs in unison with and due to the cyclicly rising and falling floats 3 and
4. As was
described in detail in my now published patent application No.
PCT/CA2009/00649, Wave-
Powered, Reciprocating Hose Peristaltic Pump, the water is alternately drawn
into the
peristaltic hose assembly 1 through an intake filter and one-way check valve
and then
forced out through a second one-way check valve, all of these components being
housed
in an assembly hereafter called the flow control assembly 6. The outflow is
then
transferred away from the pump by a fitted delivery hose assembly 7. The
apparatus is
attached via the pulley block assembly 2 to a relatively immoveable reaction
point, in this
case being a gravity anchor 8 located on the lake bed or seabed below the body
of water
in which the apparatus is installed such that the apparatus will typically
pivot on its
horizontal X and Y axes but not rotate about its vertical Z axis, the latter
in order to reduce
the potential for entanglement between the delivery hose assembly 7 and the
other
components of the apparatus.
More specifically, the peristaltic hose assembly 1 is comprised of a hose,
common
threaded hose fittings fixedly attached on each of its ends and, when
required, an optional
tensile load bearing link means as was described in my now published patent
application
No. PCT/CA2009/00649, Wave-Powered, Reciprocating Hose Peristaltic Pump. A
larger
displacement surface float 3, is fixedly attached to one end of the male-
fitted, peristaltic
hose assembly 1 by a swiveling, female-fitted, filter assembly 9 that allows
water to flow
CA 02709243 2010-04-30
freely into and out of that end of the peristaltic hose assembly 1, that end
being located
underwater below the surface float 3. The opposite end of the male-fitted
peristaltic hose
assembly 1 is fixedly attached by way of a mating, female swivel fitting 10 to
the flow
control assembly 6, which is in turn affixed to the bottom of a significantly
smaller
displacement, sub-surface float 4. Beginning with the end connected to the
surface float 3,
the peristaltic hose assembly 1 extends downward and passes freely through an
open-
ended center tube in the sub-surface float 4 whereupon it continues downward
until it
passes through a first round opening in the top the pulley block assembly 2,
following
which it becomes temporarily occluded as it bends and flattens about a freely
rotating
pulley 11 and, in this case, is also squeezed flat at location 12 by an
optional, adjacent
freely rotating compression roller 13. It then exits the top of the pulley
block assembly 2
through a second round opening and extends upwards to become attached via to a
mating
female fitting located in the housing of the flow control assembly 6. It is
noted at this time
that the aforementioned first and second openings through which the
peristaltic hose
assembly 1 enters and exits the top of the pulley block assembly 2 are called
hose
occlusion openers 14 and 15. These represent a novel aspect of the present
invention
and, therefore, are taught in the descriptions associated with subsequent
drawings, at
which time their design and function will become apparent.
The apparatus is typically installed in any suitable body of fluid such as an
ocean such that
the pulley block assembly 2 is anchored to the bottom or seabed 16 or to any
other
suitable sub-surface reaction point deemed to be fully or significantly
immoveable relative
to the undulating surface 5 that the surface float 3 tracks the movement of.
In operation, the larger displacement surface float 3 functions as what is
commonly
referred to in this field of art as a wave follower in that it follows or
tracks the surface 5 of
the body of water as it rises and falls with the waves. The smaller
displacement, less
buoyant sub-surface float 4 remains fully submerged and, therefore,
continuously strives
to rise to the surface 5. The surface float 3 and the sub-surface float 4
operate in
opposition to each other because the peristaltic hose assembly 1 to which they
are
attached, turns a nominal 180 degrees about the freely rotating pulley 11
located in the
pulley block assembly 2 such that the floats 3 and 4 both pull in the same
direction, that
CA 02709243 2010-04-30
11
being toward the surface 5. The peristaltic hose assembly 1 remains taut as it
reciprocates
back and forth through the pulley block assembly 2 because the bottom or
seabed 16 to
which it is anchored functions as a fixed reaction point and also because the
peristaltic
hose assembly 1 remains at a generally fixed length once under tension.
Because the
surface float 3 is significantly more buoyant, the sub-surface float 4 always
acts in
response to the movement of the surface float 4. Therefore, the sub-surface
float
assembly 4 is drawn down toward the bottom or seabed 16 each time the surface
float 3
moves upward with the rising waves and conversely, the sub-surface float 4
rises up
toward the surface 5 when the surface float 3 subsequently moves downward into
the
trough of the wave, and thus the cycle continues.
This results in a cyclic shortening and lengthening of that section of the
peristaltic hose
assembly 1 located between the pulley block assembly 2 and the sub-surface
float 4,
hereafter called the frontside section 17 of the peristaltic hose assembly 1
and, in reversed
sequence, a cyclic lengthening and shortening of that section of the
peristaltic hose
assembly 1 located between the pulley block assembly 2 and and the surface
float 3,
hereafter called the backside section 18 of the peristaltic hose assembly 1.
Because the peristaltic hose assembly 1 becomes fully occluded where it
temporarily
flattens out while bending about the bottom portion of the pulley 11, whether
this be due
only to the upward pull of the floats 3 and 4 or due also to it being
temporarily compressed
between the freely rotating pulley 11 and the adjacent, freely rotating
compression roller
13, water is drawn in and then pumped out, albeit in reverse order of each
other, on both
the frontside section 17 and the backside section 18 of the peristaltic hose
assembly 1 as
their internal volumes alternately increase and decrease because the pulley
block
assembly 2, and, therefore, the point of occlusion do not move up and down
with the
frontside and and backside sections 17 and 18 of peristaltic hose assembly 1.
Each time that the frontside 17 of the peristaltic hose assembly 1 lengthens
with the falling
wave, water is drawn into it through an intake filter in 19 located in the
flow control
assembly 6 and conversely, each time the frontside 17 of the peristaltic hose
assembly 1
shortens, water is forced out of it and through the one-way-out check valve in
the flow
control assembly 6, from whence it is carried away via the delivery hose
assembly 7 for
CA 02709243 2010-04-30
12
the purpose of powering and/or feeding any number or combination of downstream
driven
devices or processes. In this case, the water being pumped is being drawn from
the body
of water in which the apparatus is installed but that need not always be the
case. It is
noted that these downstream apparatus typically present a resistance to the
outflow and,
therefore, a co-responding pressure buildup in the delivery hose 7 and the
frontside 17 of
the peristaltic hose assembly 1 is required to overcome this, which the
apparatus is
designed and sized to overcome. It is also noted that the backside section's
18 pumping
capability is not employed in this case for the sake of maximizing simplicity
but it may also
be harnessed in similar fashion.
It is noted that up to this point the apparatus and its workings are the same
as described in
detail in my now published patent application No. PCT/CA2009/00649, Wave-
Powered,
Reciprocating Hose Peristaltic Pump, with the exception of the reference to
the hose
occlusion openers 14 and 15 which will be addressed in the descriptions
associated with
Fig's. 2 to 9, which deal specifically with the present invention, an improved
hose-
occluding pulley block, which is intended for use as a component within the
type of
apparatus that has been described above in Fig.1 to improve understanding.
To that end, Fig's. 2 to 9 and their associated descriptions present several
novel new
features, which may be incorporated into the present invention either
independently or in
any combination. These include (a) occlusion re-opening means (b) occlusion
widening
means (c) self-adjusting occlusion gap means (d) pressure spike release means
(e)
peristaltic hose cleaning means (f) means by which to reduce the potential for
premature
failure of a peristaltic hose due to its bending about a tight radius,
(g) convenient compression roller setup means (h) in-situ, pulley block and/or
peristaltic
hose assembly quick change means, and (i) self-providing hose occlusion force
means for
devices employing compression rollers.
To clarify further, the device taught in the description that follows can
generally be
described as an improved, hose occluding pulley block intended for a use as an
integral
component of a wave-powered, reciprocating hose, peristaltic pump wherein a
peristaltic
hose, or any other similarly acting flexible assembly incorporating a
peristaltic hose, is
reciprocally drawn back and forth through this device by opposing prime movers
such as
CA 02709243 2010-04-30
13
buoyant floats reacting to undulating wave action, this resulting in a
reciprocating flow of
water into and out of the peristaltic hose, of which the outflow can be
utilized to
accomplish work.
It is noted that from Fig. 2 to Fig. 9, the numbering of all elements
pertaining to the
present invention begins at 20. However; for all other elements previously
referenced in
Fig. 1 and shown in Fig. 2 to Fig. 9 for the sake of improved clarity but
otherwise not
pertaining directly to the present invention, the numbering remains the same
as that used
in Fig. 1.
Referring now to the embodiment of the present invention shown in Fig. 2, the
hose
occluding pulley block 20 is comprised primarily of: an open, "T" shaped, uni-
body housing
which, for greater clarity, is referred to in three sections, those being the
horizontally
oriented upper left housing 21 and upper right housing 22 and the vertically
oriented lower
housing 23; left and right hose occlusion openers 24 and 25, being vertically
oriented,
round holes with flared entry and exit openings drilled or bored through the
upper
housings 21 and 22 such that one is located on each side of the lower housing
23; a fixed
axle 26, being horizontally mounted through a slot 27 cut between locations 28
and 29 in
the lower housing 23; a freely rotating, generally flat-faced pulley or
sheave, hereafter
called the pulley 30, that rotates freely about the axle 26 within the slot
27; and a
representative anchoring means 8 to which the lower housing 23 is pivotally
attached with
a shear pin 31. The lower housing 23 may be extended in length as shown at 32
in order
to reduce exposure of the device's working parts to sediment and other means
of fouling
that is likely to be more prevalent along the bottom of most bodies of water
in which the
apparatus as a whole may be installed, as shown in Fig. 1.
A fitted peristaltic hose assembly 1 is also shown, being that it is an
integral component of
the larger apparatus within which the hose occluding pulley block 20 typically
operates, as
was shown and described in Fig. 1. Its outside diameter is slightly smaller
than the inside
diameter of the hose occlusion openers 24 and 25 through which it passes on
entering
and exiting the hose occluding pulley block 20. For greater clarity, the
peristaltic hose
assembly 1 first enters the hose occluding pulley block 20 through the first
hose occlusion
CA 02709243 2010-04-30
14
opener 24, passes through the slot 27 where it bends under and about the
pulley 30 and
then exits the hose occluding pulley block 20 through the second hose
occlusion opener
25. As the peristaltic hose assembly 1 is pulled up by it's ends against the
lower face of
the pulley 30, (in this case, by the surface and sub-surface floats 3 and 4
shown in Fig. 1),
the continuous force thus applied to the inner wall of the peristaltic hose
assembly 1
causes it to flatten out against the generally flat face of the pulley 30
between locations 33
and 34 to the degree that its normally open inner chamber will become
temporarily
occluded.
Depending on a number of factors such as the amount of force drawing the
peristaltic
hose assembly 1 up against the pulley 30, the physical characteristics of the
hose itself
and the diameter of the pulley 30, an additional means of occluding the
peristaltic hose
assembly 1 (such as the freely rotating compression roller 13 shown in Fig. 1)
may or may
not be needed to cause as well as maintain occlusion of the peristaltic hose
assembly 1
during normal operating conditions. In the embodiment of the present invention
shown
here in Fig. 2, this is not needed because a small enough diameter pulley 30
is employed,
meaning the occluding force caused by the upward pull of the peristaltic hose
assembly 1
is distributed over a small enough area on the face of the pulley 30 that
occlusion is
achieved and maintained under normal working pressure without the need for the
additional occluding means. The use of additional occluding means is, however,
shown
and described in subsequent figures.
It is noted that in general practice when bending any flexible member about a
pulley,
precautions such as increasing the bend radius by using larger pulleys or
selecting a
flexible member whose physical characteristics allow for a tighter bend radius
may be
taken in order to reduce the potential for premature failure of the flexible
member. In the
case of the devices shown here in Fig. 2 and in subsequent drawings, novel,
alternative
means are also employed to accomplish this. For example, the hose occlusion
openers 24
and 25 are aligned over the pulley 30 in such a way that the inward facing
surface or wall
of the peristaltic hose assembly 1 on either side of the pulley 30 is farther
from locations
33 and 34 than is the outward facing surface or wall between those same
points. Because
the opposite condition is true for that part of the peristaltic hose assembly
1 between
CA 02709243 2010-04-30
locations 33 and 34 where it bends about the lower portion of the pulley 30,
the averaged
lengths of the inward and outward facing walls of the peristaltic hose
assembly 1 as it
operates within the hose occluding pulley block 20 are thus the same or very
similar.
Expressed in other words, the distance measured along the wall of the
peristaltic hose
assembly 1 between the points where it enters the hose occluding pulley block
20 through
the first hose occlusion opener 24 and exits through the second hose occlusion
opener 25
after rounding the pulley 30 is the same or very similar when measured along
both it's
inside and outside surfaces. In effect, this reduces the potential for
structural failure of the
peristaltic hose assembly 1 due to such causes as unevenly distributed tensile
loading or
stretching, the likelihood of which increases as the pulley diameter decreases
with
conventional setups. By knowing the wall thickness of the peristaltic hose
assembly 1 and
the diameter of the pulley 30, the optimal distances between (a) the lower,
inside openings
of the hose occlusion openers 24 and 25 and locations 33 and 34 where the
peristaltic
hose assembly 1 is in sustained contact with the pulley 30 and (b) the
distance between
the hose occlusion openers 24 and 25 themselves can then be calculated for
optimal
configuration of the hose occluding pulley block 20.
This capability is further enhanced by using a smooth, slippery material for
the face of the
pulley 30 such that the inner wall of the peristaltic hose assembly 1 can more
easily slide
or move, whether in general or by many localized micro-movements in relation
to the face
of the pulley 30 when in contact with it, as a means of self-balancing
internal stresses.
A second novel aspect of the present invention shown in Fig. 2. involves the
use of the
aforementioned hose occlusion openers 24 and 25 to ensure full and timely
reopening of
the peristaltic hose assembly 1 following its occlusion within the hose
occluding pulley
block 20.
With conventional peristaltic pumps, it is generally understood that the hose
being
employed is capable of returning fully or near fully to its normally round,
internally open
shape following each occlusion event and before the next one occurs on its own
accord.
When used in conventional peristaltic pumps, these hoses are typically
referred to as
peristaltic hoses because they are designed to return rapidly to their normal
shape, being
CA 02709243 2010-04-30
16
that the occlusion cycle times are typically very short, with occlusion
frequency often being
hundreds of times per minute.
However, in the case of the device taught in my now published patent
application No.
PCT/CA2009/00649, Wave-Powered, Reciprocating Hose Peristaltic Pump, these
occlusion cycle times are much longer by comparison, with occlusion frequency
often
being less than ten cycles per minute. As such, a means was taught whereby
more
generally available and often lower cost hoses might also be employed, even
though their
ability to return to their normally round, internally open shape on their own
accord could
take significantly longer.
It is important to note, however, that the above opportunity has it's limits
and certain
capabilities must continue to exist. The most obvious of these is that the
hose must still be
capable of returning fully or near fully to its normally round, internally
open shape quickly
enough to draw replacement water into itself before the next occlusion occurs,
albeit more
slowly; otherwise little or no water will be available to be pumped out as
little or no
replacement water would be drawn into a hose that would remain substantially
or fully
flattened following occlusion. Less obvious, however, is that the hose may
only partially
return to it's normally round shape, in which case water will still be pumped
but at a
reduced volume meaning a loss of efficiency of the device. This could be as a
result of a
number of conditions such as (a) some but not all of the wave frequency
dependent
occlusion cycle times may be too fast for the elastic return speed of the hose
to allow it to
re-open fully each and every time (b) the elastic capabilities of the selected
hose may not
be great enough to provide the necessary internal force to fully reverse the
deformation
caused by the occlusion as well as, in so doing, provide the additional
suction force
needed to draw in a full or near full compliment of replacement water, or (c)
in a worst
case scenario, the elastic capabilities of the hose would not be enough to
provide the
momentary, additional force potentially needed to trigger or initiate
reopening of the
occlusion for some or even all pumping cycles.
In practice, the hose occlusion openers 24 and 25 are designed to address
these issues
by ensuring that a hose passing through them will be forced to return to its
normally round,
internally open state immediately following an occlusion event, thereby
improving that
CA 02709243 2010-04-30
17
hose's efficiency as well as resulting in the suitability of a broader range
of hoses,
assuming that the hoses in question embody at least the minimum amount of
elasticity
required to remain reopened to a significant degree as they continue to draw
in
replacement water. To clarify this point, a hose such as a common fire hose
would not
function with or without the benefit of this novel feature because fire hoses,
by design, do
not have the elasticity needed to cause them to take on or return to a round,
internally
open shape under any degree of suction or negative pressure.
As previously stated, the hose occlusion openers 24 and 25, are, in this
embodiment of
the present invention, comprised of two vertically oriented, round holes with
flared entry
and exit openings drilled or bored through the upper housings 21 and 22 such
that one is
located on each side of the lower housing 23. These holes have a diameter just
slightly
larger than the outside diameter of the peristaltic hose assembly 1 and
understood to be
rigid in shape, being that they are bored through the rigid housing of the
hose occluding
pulley block 20. As a result, the flexible, peristaltic hose assembly 1 is
forced to take their
shape as it moves through them, thereby causing the peristaltic hose assembly
1 to return
to it's round, fully-open shape immediately following occlusion, as it is
drawn back and
forth through the hose occlusion openers 24 and 25. Not only does this assist
the
peristaltic hose assembly 1 in creating the suction needed to draw in
replacement water,
it also sets up a condition where the return to a fully open condition is
reached. In so
doing, it also reduces the degree to which the hose may develop a memory for
remaining
progressively more flat over time and, therefore, less efficient; a condition
that is more
likely to occur if the hose never returns fully or near fully to it's initial
round shape.
This feature is further enhanced by optionally incorporating spiral ridges or
cavities 35 and
36 (shown here as heavy, dashed lines because they are hidden) into the inner
walls of
the hose occlusion openers 24 and 25. These serve the same function as rifling
in a gun
barrel, thereby causing the peristaltic hose assembly 1 to gradually turn or
rotate as it
cycles back and forth through the hose occluding pulley block 20 with the
result that
repeated flattening of the hose wall does not always occur in the same places,
thereby
reducing localized fatigue or loss of elasticity, thus extending the useable
life of the
peristaltic hose assembly 1. It is noted that for this feature to function
effectively, the
CA 02709243 2010-04-30
18
peristaltic hose assembly 1 itself or, for that matter, any components by
which it may be
attached to prime movers such as floats at each of its ends, should
incorporate swivels to
minimize resistance and limits to the ability of the peristaltic hose assembly
1 to turn thus.
Referring now to Fig. 3, this embodiment of the present invention is seen to
be similar to
that shown in Fig. 2 but with a number of novel, new features added. The first
of these is a
set of replaceable hose cleaners 37 and 38 attached to the top of the
occluding pulley
block 20 such that they are centered over the hose occlusion openers 24 and
25. In this
case, the hose cleaners 37 and 38 are each comprised of a plastic disk with a
round hole
bored through its centre, resembling a thick washer. The inside diameter of
the hose
cleaners 37 and 38 is moderately larger than the outside diameter of the
peristaltic hose
assembly 1, which passes through them as it enters and exits the occluding
pulley block
20 via the hose occlusion openers 24 and 25. Any combination of flexible
bristles,
brushes, scrapers or other appropriate means are fixedly attached to or
imbedded into the
inner walls of the hose cleaners 37 and 38 such that they extend inward to
come in
contact with the outer wall of the peristaltic hose assembly 1. As the hose
moves back and
forth through the hose cleaners 37 and 38, it is lightly scoured in order to
eliminate or at
least reduce the accumulation of biological growth and other fouling on the
peristaltic hose
assembly 1, which could interfere with the normal function of the device.
Attention is now drawn to the fact that unlike that shown in Fig. 2, the
peristaltic hose
assembly 1 shown here in Fig.3 does not become fully occluded without
additional means,
as it bends about the pulley 30 between locations 33 and 34 here in Fig. 3. In
that regard,
the next of the novel new features of the present invention relates to the
compression
roller 39 that has been incorporated into this embodiment. While the use of a
compression
roller to assure full occlusion of a peristaltic hose was first introduced in
my now published
patent application No. PCT/CA2009/00649, Wave-Powered, Reciprocating Hose
Peristaltic Pump, the version shown here represents a significant improvement
over the
prior art. To that end, a flexible, modestly compressible tire 40 is mounted
snugly over the
outer face of the compression roller 39 covering its full face with the tire's
contour
matching the face contour of the adjacent pulley 30. In this case, the
contours of both the
pulley 30 and the compression roller tire 40 are flat, however, other mating
profiles may be
CA 02709243 2010-04-30
19
used as long as the result is full occlusion of the peristaltic hose assembly
1 and that the
peristaltic hose assembly 1 is not damaged from uneven or excessive
compression.
The addition of the compression roller tire 40 accomplishes two things. First,
because the
tire is of pre-determined flexibility based on its durometer and thickness, it
flattens slightly
more at the point of occlusion than would be the case with a solid compression
roller. This
provides a means by which the width of the occlusion that occurs at location
41 when the
peristaltic hose assembly 1 is squeezed between the pulley 30 and the
compression roller
tire 40 is increased, thereby offering the ability to better maintain a seal
should
irregularities be present in the hose's thickness, shape, inner wall
smoothness or other
anomalies of similar consequence. In effect, the combination of the wider
occlusion area
and the flexible outer wall of the peristaltic hose assembly 1 increase the
ability to
maintain occlusion by surrounding and isolating the anomaly. In so doing this
also
increases the device's ability to maintain pressurized pumping in the event of
such
anomalies. In addition, it also provides a means by which the device can, to a
limited
degree, self-adjust the occlusion causing gap between the pulley 30 and the
compression
roller 39 and tire 40 assembly in order to adapt to variances in hose
construction as well
as time and usage related changes in hose thickness or other similar factors
resulting in
variation in thickness of the walls and/or diameter of the peristaltic hose
assembly 1. It is
noted that a plurality of compression rollers may be incorporated into the
pulley block 20,
whether to improve the device's ability to maintain working pressure or in
order to increase
the pressure handling capabilities of the larger apparatus that it is a part
of.
In this embodiment of the present invention, the compression roller 39 is
located directly
below and adjacent to the pulley 30. It rotates freely about an axle 42 that
passes through
the slot 27 cut between locations 28 and 43 in the lower housing 23. In order
to facilitate
insertion of the peristaltic hose assembly 1, as well as to allow for
adjustment of the gap
between the pulley 30 and the compression roller 39 and tire 40 assembly, the
axle 42 is
mounted into slots 44 and 45 (the latter hidden) in the lower housing 23, one
slot being on
each side of the compression roller 39. The axle 42, which may be a bolt, is
threaded on
at least one end with the threads extending out beyond the lower housing 23.
Once the
the compression roller 39 and tire 40 assembly is pressed against the
peristaltic hose
CA 02709243 2010-04-30
assembly 1 with enough force to cause full occlusion, a locking means, in this
case being
a wing nut 46, is tightened onto the threads in order to lock the axle 42 in
place. The
known technique of using a series of either raised ridges or grooves 47 that
interact with
mating features on the wing nut 46 is used here to eliminate gradual slippage
of the axle
that could otherwise occur over time, thus leading to a loss of full occlusion
of the
peristaltic hose assembly 1 and, therefore, pumping capability.
A related novel feature addresses the issue of how to evenly apply, adjust and
hold the
forces that need to be applied to the lower side of the compression roller 39
and tire 40
assembly in order to flatten the peristaltic hose assembly 1 to the proper
degree needed to
achieve optimal occlusion. To that end, an axle 48 is fixedly mounted into the
lower
housing 23 such that it passes through the slot 27 below the compression
roller 39 and a
small, freely rotating roller 49 is mounted onto it. In this way a tapered
wedge can be
inserted through the slot 27 between the non-slidable, small roller 49 and the
slidable
compression roller 39 and tire 40 assembly and pushed or driven between them
such that
its progressively thicker cross section forces the compression roller 39 and
tire 40
assembly in a controlled fashion against the peristaltic hose assembly 1 to
the degree
needed to achieve full occlusion, at which time the wing nut 46 is tightened
to lock the
compression roller 39 and tire 40 assembly in place.
Referring now to Fig. 4, while seen from a lower viewing angle, this
embodiment of the
present invention is similar to that taught in Fig. 3 with the significant
difference being the
means used to adjust the gap between the pulley 30 and the compression roller
39. For
greater clarity, this view shows a portion of lower housing 23 of the
otherwise complete
pulley block 20 as being cut away between locations 50 and 51 and shows the
compression roller 39 as a dashed line, also for greater clarity.
As was the case with the embodiment taught in Fig. 3, the compression roller
39 shown
here in Fig. 4 is located directly below and adjacent to the pulley 30 and
rotates freely
about an axle 42 that passes through the slot 27 cut between locations 28 and
43 in the
lower housing 23. Similarly, the axle 42 is mounted into slots 52 and 53 (the
former being
hidden) in the lower housing 23, one slot being on each side of the
compression roller 39.
Again, this is in order to facilitate insertion of the peristaltic hose
assembly 1 as well as to
CA 02709243 2010-04-30
21
allow for adjustment of the gap between the pulley 30 and the compression
roller 39.
However, in this case, the slots 52 and 53 are cut into but do not extend
fully through the
lower housing 23 on either side of the compression roller 39. The length of
the unthreaded
axle 42, is just slightly less than the distance between the bottoms of the
two slots 52 and
53 which, combined with the flat, smooth ends with slightly rounded edges of
the axle 42,
allows it to slide up and down within the slots 52 and 53 such that the freely
rotating
compression roller 39 mounted on it can slide up and down toward and away from
the
pulley 30 in order to facilitate insertion of the peristaltic hose assembly 1,
as well as to
allow for adjustment of the gap between the pulley 30 and the compression
roller 39.
Each end of the axle 42 sits upon one of two gap adjustment assemblies 54 and
55. While
only the rearward of these two assemblies is shown here due to the cutaway
view, it is
understood that each can be adjusted separately. As with the hidden gap
adjustment
assembly 55, the gap adjustment assembly 54 is comprised of an unthreaded push
rod 56
linked to a replaceable compression member 57 which is in turn linked to a
threaded
machine screw 58 whose threads are matched to internal threads cut into the
lower
portion of the slots 52 and 53 such that the adjustment assembly travels up
and down
when the head 59 of the machine screw 58 is turned. In order to access the
machine
screw head 59 as well as to insert the axle 42 into the slots 52 and 53, a
larger slot 60 is
cut completely through the lower housing 23 such that the lower ends of the
slots 52 and
53 open into it, thus allowing access to the slots 52 and 53 for assembly
purposes and
access to the heads of the two gap adjustment assemblies 54 and 55 for setup
and fine
tuning.
In this way, the adjustment assemblies can be used to raise and lower the axle
42 and
compression roller 39 as needed, whether for mounting the peristaltic hose
assembly 1 or
for adjusting the gap between the pulley 30 and the compression roller 39 to
establish
proper occlusion of the peristaltic hose assembly 1. The compression member 57
is, in
this case, a firm rubber cylinder with an inside diameter sized to allow the
machined down
ends of the push rod 56 and the machine screw 58 to be pressed partially into
it from each
end, but other similarly acting members could also serve this purpose. Because
the
compression member 57 is flexible, hollow and smaller in diameter than the
slot in which it
CA 02709243 2010-04-30
22
is located, it can distort outward in it's middle cross section, thereby
allowing it to
compress and shorten vertically. This in turn allows the push rod 56 and the
axle 42 riding
upon it to be forced downward, away from the pulley 30 to a pre-determined
degree as a
means of (a) self-adjusting for variations or changes over time in the
thickness of the
peristaltic hose assembly 1 in order to maintain appropriate occluding forces
and gap, and
(b) providing a means of relieving excessive buildup, spikes or surges in
pressure within
the peristaltic hose assembly 1 by momentarily opening the occlusion at
location 41 until
the excessive pressure condition has passed. It is recalled that there are two
adjustment
assemblies so mounted and attached to each end of the axle 42 so in this way,
the
compression roller 39 can not only be raised and lowered but its face angle
can also be
adjusted to match that of the adjacent pulley 30 in order to optimize
occlusion.
Referring now to Fig. 4a, an alternative style of adjustment assembly is
shown. While it's
function and capabilities are the same as the gap adjustment assembly 54 shown
in Fig.
4, this version can also be installed in pairs on the outside walls of the
lower housing 23,
meaning the lower slot 59 as was seen in Fig. 4 is not required for adjustment
access.
Instead, the slots 52 and 53 are cut clear through each side of the lower
housing 23 and
the axle 42 extends out beyond each side of the lower housing. For greater
clarity, it can
be seen that the adjustment assembly is, in fact, a common turnbuckle with the
only
modification being that the eye portion of its lower, threaded member has been
removed
such that the remaining threaded portion can be pressed into the compression
member 57
which serves the same function as the one that was shown in Fig. 4. More
specifically, the
eye located on the upper end of this turnbuckle adjustment assembly 61 is slid
over the
frontward facing end of the axle 42 and prevented from slipping off in this
case by press
fitting a retaining nut (not shown for the sake of clarity) onto that end of
the axle 42. The
lower threaded element of the turnbuckle adjustment assembly 61 is pressed
into the top
opening of the previously described compression member 57 and optionally
bonded
therein. The bottom opening of the compression member 57 is then pressed over
and
optionally bonded to an upward oriented, cylindrically shaped pin portion of a
retainer
block 62 that is fixedly attached with a fastener 63 to the surface of the
lower housing such
that the turnbuckle adjustment assembly 61 either lengthens or shortens
depending on
which way its nut 64 is turned. Because the retainer block 62 is immovably
fixed to the
CA 02709243 2010-04-30
23
lower end of the turnbuckle adjustment assembly 61, the axle 42 and
compression roller
39 are forced to move either up or down, or in other words closer to or
farther from the
pulley 30 because it is captive within the eye on the threaded upper member of
the
turnbuckle adjustment assembly 61. It is recalled that there are two
adjustment
assemblies so mounted and attached to each end of the axle 42. As with the
device taught
in Fig. 4, the compression roller 39 can in this way, not only be raised and
lowered but its
face angle can also be adjusted to match that of the adjacent pulley 30 in
order to optimize
occlusion.
Referring now to Fig. 5, this embodiment of the present invention is also
shown with the
main housing of the occluding pulley block 20 being partially cut away between
locations
50 and 51 for greater clarity. Thus, it can be seen that the single,
compression roller 39
shown previously as being located directly below the pulley 30 in Fig. 3 and
Fig. 4 has
been replaced here in Fig. 5 by two compression rollers 65 and 66 located
diagonally
above and to either side of the pulley 30 with the gap between them being less
than the
diameter of the pulley 30. The first compression roller 65 rotates freely on
an axle 67 that
is fixedly mounted to the upper left housing 21 and the second compression
roller 66
rotates freely on an axle 68 that is fixedly mounted to the upper right
housing 22.
As with the previously taught embodiments, the freely rotating pulley 30 is
seen to be
mounted on an axle 42 shown here again being slideably mounted into a
frontside slot 44
(not shown due to cutaway) and backside slot 45 (hidden so shown as a dotted
line) for
adjustment purposes, after which the axle 42 is locked in place by a fastener
such as a
wing nut 46. Likewise also, the pulley 30 and, in this case, both compression
rollers 65
and 66 are mounted within a slot 27 located between location 28 seen spanning
the upper
left housing 21 and upper right housing 22 on the top and location 29 in the
lower housing
23 on the bottom. As with the previously taught embodiments, the peristaltic
hose
assembly 1 is compressed against the pulley 30 to the extent that it
temporarily becomes
fully occluded as it is drawn back and forth through the gaps between the
pulley 30 and
the compression rollers 65 and 66 as can be seen at locations 69 and 70.
The functional difference between this embodiment and those taught in Fig. 3
and Fig. 4
is that occlusion of the peristaltic hose assembly 1 occurs as a result of the
pulley 30
CA 02709243 2010-04-30
24
being drawn up against the compression rollers 65 and 66 by the peristaltic
hose
assembly 1 as opposed to occlusion occurring as a result of one or more
compression
rollers being pressed against the peristaltic hose assembly 1 by an external
force. It is for
this reason that in the embodiment shown here in Fig. 5, the wing nut 46 is
used to lock
the axle 42, and therefore the roller 30, in a position that limits the amount
of compression
being applied to the peristaltic hose assembly 1 in order to eliminate damage
and/or loss
of efficiency that could occur due to over compression.
Referring now to Fig. 6, this embodiment of the present invention is seen to
be similar to
that shown in Fig. 5 with the difference being in the means by which
compression of the
peristaltic hose assembly 1 is limited. In this embodiment, the pulley 30 and
axle 42 are
allowed to slide freely up and down within the slots 44 and 45 rather than
being locked into
the appropriate location for optimal occlusion, whether by a fastener such as
a lock nut as
was taught in Fig. 5 or by any other means. Rather, some other form of pulley
travel limiter
such as, but not limited to the freely rotating roller 71 shown here mounted
onto an axle 72
may be mounted at an appropriate location above the pulley 30 such that the
faces of the
roller 71 and pulley 30 come into contact with each other, thereby preventing
further travel
of the pulley 30 at that point where full occlusion of the peristaltic hose
assembly 1 is
determined to occur. Adjustability of the occluding gaps is also incorporated
by mounting
the axle 72 into a frontside slot 73 (not shown due to cutaway) and a backside
slot 74 and
then locking it in the appropriate location with a fastener such as a wing nut
75 (hidden). In
this way, the temporary compression and occlusion of the peristaltic hose
assembly 1
between the pulley 30 and compression rollers 65 and 66 at locations 69 and 70
respectively can be both limited and adjustably controlled.
Referring now to Fig. 7, this embodiment of the present invention is shown in
the same
cutaway view and seen to be similar to that shown in Fig. 6 with the only
difference being
that the pulley 30 is not mounted on an axle as was taught in Fig. 5 and Fig.
6 but rather
is inserted into and allowed to float freely within the aforementioned slot 27
in the lower
housing 23. This further facilitates mounting of the peristaltic hose assembly
1 which, as
was previously taught, wraps under the pulley, thereby drawing it up and
holding it in the
correct position to cause occlusion of the peristaltic hose assembly 1 when in
operation.
CA 02709243 2010-04-30
The width of the slot 27, being only slightly more than the width of of the
pulley 30,
prevents twisting or racking of the pulley 30, which could result in
misalignment with the
compression rollers 65 and 66 to the degree that a loss of occlusion or uneven
wear might
occur. The compression rollers 65 and 66 are spaced far enough apart that the
pulley 30
can enter the gap between them far enough to prevent it from slipping out of
the device
under intended operating conditions. It is foreseen that a similar embodiment
excluding
any form of hose compression limiting means could function in limited
circumstances.
Referring now to Fig. 8, this embodiment of the present invention is comprised
of a
conventional, fiddle block style housing 76 rather than an open, "T" shaped,
uni-body
housing as taught in the previous Fig's 1 to 7; a flat-faced, freely rotating
pulley 30 that
provides the necessary amount of compression force needed to cause and
maintain
occlusion without the use of a compression roller, as was previously taught in
Fig. 2 and;
a discrete hose occlusion opener 77, in this case attached to the upper end of
the housing
76 between its front cheek 78 and back cheek 79 by a fastener 80 such as a pin
or bolt
and such that the hose occlusion opener 77 can partially rotate around the
fastener 80 on
the same plane as the pulley 30 operates on. It is noted that while the fiddle
block style
housing 76 used in this embodiment of the present invention is different than
those
housings taught in the previous figures, it and the device in general,
function in the same
manner as those previously taught. It is noted that for the sake of clarity,
the hidden
portion of the peristaltic hose assembly 1 and the hidden pulley 30 are marked
by a
dashed lines.
Referring now to Fig. 8a, it is envisioned that for convenience and cost
considerations,
a common, conventional fiddle block could be adapted for the novel use taught
herein by
replacing its conventional pulley with one capable of and intended for
occluding a hose,
such as the relatively flat-faced pulley 30 shown here Fig. 8a as well as by
adding some
form of hose occlusion opener 76 such as those shown here Fig. 8a.
Referring finally to Fig. 9, this embodiment of the present invention shows
yet another
housing that can be used while still employing the same operating principles
and some or
all of the previously taught novel features. In this case, the housing 81
employed is what is
commonly referred to as a snatch block, meaning that at least one of its
cheeks is hinged
CA 02709243 2010-04-30
26
or similarly configured such that it can be opened in order to allow a
flexible member such
as a rope, cable or, in this case, a peristaltic hose assembly 1 to be mounted
more easily
and without having to disassemble the flexible member from the apparatus as a
whole.
More specifically, the bottom of the front cheek 82 is attached by a hinge 83
to the bottom
of the back cheek 84 of the housing 81. Appropriate fasteners, in this case
being threaded
pins 85 and 86 are fixedly attached to the back cheek 84. When the two cheeks
are closed
against each other as shown at the joint 87, these pins 85 and 86 protrude
through aligned
holes (hidden) in the front cheek 82 whereupon fasteners, which in this case
are wing nuts
88 and 89, are used to lock the two cheeks 82 and 84 together. To further
facilitate in-situ
servicing or replacement of this style of hose occluding pulley block, a
removable,
threaded shear pin 90 and wing nut 91 are employed to mount it to any
appropriate
anchoring means 8. The primary benefit of this design is to allow for easier
in-situ
replacement of the complete hose occluding pulley block 92 and or the
peristaltic hose
assembly 1.
Referring now to the preceding drawings and their descriptions in general, it
is envisioned
that these hose occluding pulley blocks may, as is common practice with
conventional
pulley blocks, incorporate raised ridges into the inner walls of the housings
or use other
similar means for the purpose of preventing the peristaltic hose assemblies
from sliding or
being extruded into the gaps that must exist between the sides of the pulleys
and the inner
walls of the housing in which they rotates.
It is noted that as with the various hose assemblies taught in my now
published patent
application No. PCT/CA2009/00649, Wave-Powered, Reciprocating Hose Peristaltic
Pump, the peristaltic hose assemblies referred to in this description of the
present
invention may or may not incorporate a discrete, woven linkage or some other
similarly
acting strength member whose purpose is to carry most or all of the tensile
loads that
would otherwise be borne by the peristaltic hose assembly 1 during operation.
This does
not change the operating principles, function or design of the present
invention.
Claims - to follow
