A magnetically-driven pump transferring fluid through a conduit is provided, having an electromagnet assembly selectively excited by a power source, and a non-ferromagnetic lever structure extending from the electromagnet assembly to the conduit, the lever structure having a ferro-magnetic portion, which may consist of a plate, at one end movable by the electromagnet assembly between a release position where the ferro-magnetic portion is angularly offset relative to the electromagnet assembly and a compression position where the ferro-magnetic portion is in substantially parallel contact with the electromagnet assembly, the ferro-magnetic portion enabling a striker portion at another end of the lever structure to compress the conduit at a predetermined frequency. The lever structure couples movement of the ferro-magnetic portion at one end with movement of a striker at the other end such that the ferro-magnetic portion moves within a lesser arcuate range and the striker moves within a greater arcuate range. To reduce operating noise, the lever may be pivotally mounted on a translating shaft, enabling a part of the ferro-magnetic portion to remain in contact with the electromagnet assembly while in and between the release and compression positions.

FIELD OF THE INVENTION 
This invention relates generally to pumps, in particular, to 
magnetically-driven pulsation pumps. 
BACKGROUND AND SUMMARY OF THE INVENTION 
Pumps delivering relatively small amounts of fluid are known. Such pumps 
typically employ fluid elements, such as elastic tubes or diaphragms, to 
draw and deliver fluid at a predetermined rate. These pumps may be 
magnetically driven, employing bipolar or dipole magnets (magnets having 
two opposite poles widely spaced at opposing edges or ends) for 
compressing the diaphragms or tubes. Although such magnets provide 
relatively extensive magnetic fields, the corresponding magnetic forces 
are weak. These pumps typically incorporate specially manufactured 
components and require substantial power to operate. Moreover, they are 
particularly noisy in operation. 
Also known are peristaltic pumps employing rotating disks with protrusions 
which pinch circumscribing rubber tubes to pump fluid at a rate 
proportional to the rotation frequency of the disks. Peristaltic pumps are 
popular in the medical field, especially for intravenous medication or 
dietary supplements. Although such pumps are relatively quiet, they are 
also costly and complex in structure. Furthermore, because the tubes are 
repeatedly exposed to the protrusions on the rotating disk, the tubes must 
be replaced frequently. 
Specific examples of known pumps are discussed, for example, in U.S. Pat. 
No. 3,171,360, issued to Walton. Therein, a vibration pump is disclosed, 
having a resilient tubular conduit and a striker reciprocable at a high 
frequency against one side of the tubular conduit, a support opposite the 
area of impact of the striker having an engaging face inclined at an acute 
angle relative to the tubular conduit, and means for reciprocating the 
striker at high frequency and through a short stroke relative to the 
diameter of the tubular conduit. 
Also, in U.S. Pat. No. 4,014,318, issued to Dockum, et al., a circulatory 
assist device and structure are disclosed, providing an electrically 
operated plunger momentarily occluding the blood vessel to effect pumping, 
wherein a plurality of assist devices may be mounted adjacent each other 
and are sequentially actuated to occlude adjacent segments of the 
associated blood vessel, thereby creating a pumping action. 
Moreover, a non-sucking pulsatile outflow continuous inflow pump is 
disclosed in U.S. Pat. No. 3,518,003, issued to Anderson, consisting of a 
first distensible body forming a chamber which is flat in cross-section 
when the body is in repose, this first body serving as a ventricle 
chamber, means forming an inlet and an outlet to the chamber, the inlet 
interconnecting the ventricle with an atrium comprised of an additional 
distensible body, and valves and impellers associated with the ventricle 
and atrium chambers arranged for synchronous operation of the valves and 
impellers to produce a pulsatile discharge from the ventricle outlet and a 
continuous unrestricted inflow of liquid to the atrium. 
As indicated, these pumps are substantially complex in structure and 
require special components which increase their cost and maintenance. In 
particular, where dipole or bi-polar magnets are utilized to supply the 
necessary magnetic force to drive such pumps, the pumps can become quite 
expensive. 
Accordingly, there exists a demand for a simple and quiet 
magnetically-driven pump that is relatively inexpensive to manufacture and 
operate. It is desired that such a magnetically-driven pump use 
inexpensive, off-the-shelf components, but provide enough force to pump 
fluid to a substantial height. It is also desired that such a 
magnetically-driven pump be compact and light. It is further desired that 
such a magnetically-driven pump be energy-efficient, requiring low voltage 
and current for operation, and be appropriate for personal use with 
minimal operating noise. 
In accordance with the present invention, a magnetically-driven pump 
transferring fluid through a conduit is provided, having an electromagnet 
assembly selectively excited by a power source, and a non-ferromagnetic 
lever structure extending from the electromagnet assembly to the conduit, 
the lever structure having a ferro-magnetic portion at one end movable by 
the electromagnet assembly between a release position where the 
ferro-magnetic portion is angularly offset relative to the electromagnet 
assembly and a compression position where the ferro-magnetic portion is in 
substantially parallel contact with the electromagnet assembly, the 
ferro-magnetic portion enabling a striker portion at another end of the 
lever structure to compress the conduit at a predetermined frequency. The 
lever structure couples movement of the ferro-magnetic portion at one end 
with movement of a striker at the other end such that the ferro-magnetic 
portion moves within a lesser arcuate range and the striker moves within a 
greater arcuate range. To reduce operating noise, the lever may be 
pivotally mounted on a translating shaft, enabling a part of the 
ferro-magnetic portion to remain in contact with the electromagnet 
assembly while in and between the release and compression positions. 
These, as well as other features of the invention, will become apparent 
from the detailed description which follows, considered together with the 
appended drawings.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS 
As indicated above, detailed illustrative embodiments are disclosed herein. 
However, structures for accomplishing the objectives of the present 
invention may be detailed quite differently from the disclosed 
embodiments. Consequently, specific structural and functional details 
disclosed herein are merely representative; yet, in that regard, they are 
deemed to afford the best embodiments for purposes of disclosure and to 
provide a basis for the claims herein which define the scope of the 
present invention. 
FIG. 1 illustrates a preferred embodiment of a pump 10 for transferring 
fluid from a source 12 to a sink 14. For instance, the sink 14 may be an 
aquarium into which the pump 10 delivers water or chemicals at a 
predetermined rate. In accordance with the present invention, the pump 
provides a tubular conduit 16 through which the fluid travels, and an 
electromagnet assembly 18 positioned somewhat remotely from the conduit 16 
to drive a lever structure L extending from the assembly 18 to the conduit 
16. The lever structure L is configured to compress the conduit 16 when 
the electromagnet assembly 18 is in an excited state, and to release the 
conduit 16 when the electromagnet assembly 18 is in an unexcited state. 
Where the conduit 16 is constructed of a material providing a preselected 
resilience or elasticity, e.g., Neoprene.RTM., the conduit 16 
substantially expands or rebounds to its original shape when it is 
released from compression. Accordingly, the conduit 16 may be alternately 
compressed and released to pump the fluid from the source 12 to the sink 
14. To that end, check valves 17 are provided to regulate the direction of 
flow in the conduit 16. 
The conduit 16 may have an inflow segment 22 extending from the source 12 
to the pump 10, an outflow segment 24 extending from the pump 10 to the 
sink 14, and a center segment 26 therebetween, extending through the pump 
10. The center segment 26 is supported in the pump 10 against a conduit 
abutment 28 opposing a striker abutment 30 (see FIG. 2). A housing 32 has 
side panels 34 affixed to a base panel 36 and is provided to enclose and 
support the pump 10. 
As more clearly shown in FIG. 2, the electromagnet assembly 18 is rigidly 
affixed to one of the side panels 34 of the housing 32. The electromagnet 
assembly 18 is connected via wires or coils 38 to a power source 40 
controlled by a controller 42, e.g., a circuit board, via a wire 39, for 
driving the electromagnet assembly 18 at a predetermined frequency, which 
may be relatively low, for instance, less than 100 Hz, ranging between 40 
and 60 Hz. Typically, the frequency may be approximately 60 Hz. 
The electromagnet assembly 18 may include any readily-available flat-faced 
electromagnet operable with low voltage and current, e.g., 12 VDC and 0.5 
amp., to supply a contact holding power of at least approximately 45 kgs. 
Being flat-faced and of a substantially rectangular configuration, the 
electromagnet assembly 18 is relatively simple in design and typically 
inexpensive. Moreover, by providing a planar surface 44 having a magnetic 
field with two poles, e.g., south poles, positioned at edges 45 of the 
planar surface 44, and opposite poles, e.g., north poles, positioned in a 
center region 47 (see FIG. 2B), the electromagnet assembly 18 provides a 
magnetic field with a relatively higher flux in the area adjacent the 
planar surface 44, but with relatively shorter reach than bi-polar or 
dipole magnets. In that sense, the electromagnet assembly 18 performs 
extremely well in attracting adjacent planar structures. 
The non-ferromagnetic lever structure L includes a bar 46 extending 
substantially the length of the pump 10, from the electromagnet assembly 
18 to the center segment 26 of the conduit 16. An end 48 of the bar 46 
adjacent the center segment 26 provides a striker S facing the center 
segment 26. The other end 52 of the bar 46 adjacent the electromagnet 
assembly 18 provides a ferro-magnetic portion 54 facing the planar surface 
44 of the electromagnetic assembly 18. The ferro-magnetic portion 54 may 
be a ferro-magnetic plate member P affixed to the bar 46. The lever 
structure L adjacent the end 52 is pivotally mounted on a shaft F 
extending between the side panels 34, such that the plate member P may be 
movable between a release position (solid lines) and a compression 
position (broken lines). 
In the embodiment shown in FIG. 2, the release position involves both the 
lever structure L and the plate member P being substantially angularly 
offset from the planar surface 44 of the electromagnet assembly 18. Where 
the plate member P is in the release position, the striker S substantially 
releases the center segment 26 from compression and an angle .alpha. 
defined between the plate member P and the electromagnet assembly 18 is at 
a selected maximum, for example, up to 3.0 degrees, preferably 1.3 degrees 
for the disclosed embodiments. 
Also in the embodiment of FIG. 2, the compression position involves the 
lever structure L being substantially parallel to the planar surface 44 
and the plate member P being substantially in parallel contact with the 
planar surface 44. Where the plate member P is in the compression 
position, the striker S substantially compresses the center segment 26 
against the conduit abutment 28 and the angle .alpha. is at a minimum, for 
example, zero. 
As the plate member P moves between the two positions, a stroke of the pump 
10 may be defined as the plate member P moving from the release position 
to the compression position, and back to the release position. As the 
lever structure L pivots with the plate member P moving between the two 
positions, it can be seen that the plate member P moves in a lesser 
arcuate range R.sub.P while the end 48 bearing the striker S moves in a 
greater arcuate range R.sub.ST. By varying the length of the bar 46, 
different ratios of the greater arcuate range R.sub.ST to the lesser 
arcuate range R.sub.P may be obtained. 
In the art of magnetics, an operating proximity may be defined between an 
object and a magnet as a proximity or distance within which the object and 
the magnet may be movably attracted to come into contact with each other. 
As such, there exists an operating proximity OP for the plate member P and 
the electromagnet assembly 18 of the pump 10. In recognition of this 
operating proximity OP, it is essential that the lesser arcuate range 
R.sub.P of the plate member P remains comparable with the operating 
proximity OP of the pump 10. Otherwise, the electromagnet assembly 18 will 
be unable to movably attract the plate member P for moving the plate 
member P into the compression position to pump the fluid. For the 
disclosed embodiment, where the electromagnet assembly 18 substantially 
operates on 12 VDC and 0.5 amp, the planar surface 44 being 40 mm.times.60 
mm, and the plate member P being substantially between 3.2 mm and 6.4 mm 
in thickness, and 50 mm.times.75 mm, the operating proximity OP of the 
pump 10 may range up to 3 mm or more, but preferably at 1 mm. To that end, 
the operating proximity OP of approximately 1 mm enables the disclosed 
embodiment of the electromagnet assembly 18 to provide an attracting force 
or power of approximately 2-3 kgs or more. 
Because the electromagnet assembly 18 of the present invention operates 
with minimal voltage and current, the resulting operating proximity OP of 
the pump 10 is relatively small in comparison to conventional 
magnetically-drive pumps. While the operating proximity OP may be 
increased by increasing the power of the electromagnet assembly 18, 
resulting increases in manufacturing and operating costs undermine the 
advantages provided by the present electromagnet assembly 18. 
Notwithstanding the smaller operating proximity OP of the pump 10, the 
pump 10 provides sufficient compressive force to effectively pump 10 the 
fluid, as explained below in detail. 
With the relatively small operating proximity OP of the pump 10 and thus 
the lesser arcuate range R.sub.P of the plate member P, the lever 
structure L necessarily couples the plate member P to the striker S to 
provide the greater arcuate range R.sub.ST in the latter. That is, while 
the lesser arcuate range R.sub.P should remain comparable to the operating 
proximity OP of the pump 10, the greater arcuate range R.sub.ST should 
sufficiently accommodate the conduit 16 for compression and release. Since 
the striker S is provided at the end 48 of the bar 46, the greater arcuate 
range R.sub.ST should enable the striker S to effectively compress and 
release the center segment 26. Where the conduit 16 has an outer diameter 
of approximately 13 mm, and inside diameter of approximately 10 mm in 
diameter, the greater arcuate range R.sub.ST should be comparable to 3 mm. 
As indicated, a particular ratio of the greater arcuate range R.sub.ST to 
the lesser arcuate range R.sub.P may be provided by selecting the bar 46 
to be a particular length. Where the disclosed embodiments set forth the 
ratio between the greater arcuate range R.sub.ST to the lesser arcuate 
range R.sub.P to be substantially 3 mm:1 mm, the bar 46 should be 
approximately 12.5 cm in length. As such, the lever structure L may pivot 
about the shaft F to enable the plate member P to remain substantially in 
the operating proximity OP and the striker S to effectively compress and 
release the center segment 26. 
At this point, it is noted that although the greater arcuate range R.sub.ST 
of the striker S should sufficiently accommodate the conduit 16, the 
striker S may be permitted to remain in contact with the center segment 26 
throughout the stroke of the pump 10. To that end, the striker abutment 30 
is spaced a selected distance D from the conduit abutment 28 for 
preventing the lever structure L from pivoting beyond the maximum angle 
.alpha. and thus losing contact with the center segment 26. Consequently, 
the end 48 of the bar 46 remains between the abutments 28 and 30 during 
the stroke. 
Being susceptible to magnetic forces, the plate member P enables the 
electromagnet assembly 18 to drive the lever structure L. Consequently, 
where the controller 42 signals the power source 40 to excite the coils 
38, the energized electromagnet assembly 18 draws the plate member P into 
the compression position, pivoting the lever structure L in one direction. 
With the plate member P being in parallel contact with the electromagnet 
assembly 18 over substantially the planar surface 44, the lever structure 
L is positioned for the striker S to compress the center segment 26. The 
check valves 17 positioned on opposing sides of the center segment 26 
regulate flow in the conduit 16 such that the fluid expressed from the 
center segment 26 as a result of the compression flows toward the outflow 
segment 24, and ultimately into the sink 14. 
Where the coils 38 are in an unexcited state with the electromagnet 
assembly 18 deenergized, the plate member P is released by the 
electromagnet assembly 18 to be moved into the release position. With the 
plate member P being released by the electromagnet assembly 18, the center 
segment 26 is given the opportunity to elastically rebound from the 
compression. Consequently, as the center segment 26 expands under its own 
elasticity, it pushes the striker S toward the striker abutment 30 and the 
lever structure L pivots in an opposite direction to position the plate 
member P angularly offset from the planar surface 44. The check valves 17 
regulate flow in the conduit 16 such that additional fluid from the source 
12 is drawn into the center segment 26 as it rebounds. 
For pumping the fluid at the predetermined rate, the plate member P 
alternates between the compression position and the release position, 
pivoting the lever about the shaft F and compressing and releasing the 
center segment 26. As the power source 40 controlled by the controller 42 
intermittently excites the coils 38 at a frequency coinciding with the 
predetermined rate at which the fluid is transferred, the center segment 
26 is alternately compressed and released at the excitation frequency. 
As indicated earlier, notwithstanding the smaller operating proximity OP of 
the pump 10, the pump 10 provides sufficient compressive force to 
effectively transfer the fluid from the source 12 to the sink 14, even 
where the sink 14 is at a significantly greater height h than the source 
12. To that end, the pump 10 applies the nonlinear characteristic of 
magnetic forces to its advantage for efficiency and economy. 
As known in the art, the magnetic force between the electromagnet assembly 
18 and the plate member P is nonlinear. That is, the magnetic force 
increases quadratically as the plate member P approaches the 
electromagnetic assembly 18, where a relatively significant magnetic force 
is present when the plate member P is in substantially parallel contact 
with the electromagnetic assembly 18 over the planar surface 44. In 
accordance with the present invention, such significant magnetic force 
applies significant compression in the stroke of the pump 10. This feature 
enables the pump 10 to transfer the fluid to substantial heights, for 
instance, at least a height of approximately 3.5 m from the source 12 to 
the sink 14. 
While the elastic force of the conduit 16 opposes the compression during 
the stroke, it increases only linearly, as opposed to the magnetic force 
behind the compression which increases quadratically. Consequently, once 
the plate member P is movably drawn toward the electromagnet assembly 18, 
the lever structure L is driven with rapidly increasing magnetic force for 
moving the lever structure L from the release position to the compression 
position. Although a dramatic increase in magnetic force is necessary to 
further compress the center segment 26 once its inner surface 60 meets, 
such further compression is not necessary for the pump 10 to effectively 
transfer the fluid. The stroke of the pump 10 requires neither absolutely 
full compression of the conduit 16 nor absolutely full rebound of the 
conduit 16 to its original shape. Moreover, since the compressive force is 
applied as pressure on the conduit 16, the smaller the diameter of the 
conduit 16, the greater the compressive pressure per unit area of the 
compressed center segment 26. 
To summarize the above, the pump 10 minimizes manufacturing and operating 
costs by being simplistic in structure and design, and utilizing minimal 
power. Although such minimal power substantially limits the operating 
proximity OP of the pump 10, the pump 10 employs the lever structure L to 
couple the respective movements of the plate member P and the striker S 
such that the lesser arcuate range R.sub.P of the plate member P may be 
maintained while the greater arcuate range R.sub.ST of the striker S is 
substantially maximized. 
As suggested earlier, the release position of the plate member P relative 
to the planar surface 44 should be substantially comparable to the 
operating proximity OP for the pump 10 to operate with optimum efficiency. 
However, the pump 10 actually requires only that an average distance A 
taken between the electromagnet assembly 18 and the plate member P be 
substantially comparable to the operating proximity OP. In that respect, 
the angularly-offset release position of the plate member P does not 
adversely affect the ability of the electromagnet assembly 18 to draw the 
plate member P into the compression position, provided that the average 
distance A is comparable to the operating proximity OP. In fact, such 
angularly-offset release position facilitates compression of the center 
segment, as explained in the following example. 
For instance, referring to FIG. 2A, by positioning a midpoint MP on the 
plate member P (in the release position) substantially at the operating 
proximity OP, a left section LS is significantly closer to the 
electromagnet assembly 18, while a right section RS is significantly 
farther from the electromagnet assembly 18. While the average distance A 
is still comparable to the operating proximity OP, the left section LS 
experiences an increase in magnetic force which is greater than the 
decrease in magnetic force experienced by the right section RS. 
Consequently, a net increase in the magnetic force over the plate member P 
facilitates the compression of the center segment. In the disclosed 
embodiment, the angularly-offset release position of the plate member P 
provides a relatively greater magnetic force than the substantially 
parallel release position present in typical magnetically-drive pumps. 
Accordingly, the pump 10 operates efficiently by capitalizing on the 
particular characteristics of magnetic forces. 
Whereas conventional pumps generate substantial noise from components being 
driven in and out of contact, the pump 10 generates minimal noise. In 
particular, the lever structure L is positioned relative to the 
electromagnet assembly 18 such that an edge portion E of the left section 
LS remains in contact with the electromagnet assembly 18 throughout the 
stroke. Consequently, as the plate member P moves into the compression 
position, the edge portion E thereof "pushes against" the electromagnet 
assembly 18 so that the plate member P is able to come into parallel 
contact with the electromagnetic assembly 18 over substantially the planar 
surface 44. When the plate member P moves into the release position, the 
edge portion E "pushes off" the electromagnet assembly 18 so that the 
plate member P is able to rest in the angularly-offset position relative 
to the electromagnet assembly 18. The edge portion E of the plate member P 
thus remains in contact with the electromagnet assembly 18 to reduce 
operating noise of the pump 10. And, in addition to reducing noise, the 
contact between the edge portion E and the electromagnetic assembly 18 
also enables the pump 10 to utilize the power of the electromagnet 
assembly 18 well within the operating proximity OP. 
Furthermore, cushioning material, such as foam, and the like, may be 
provided on various points of contacts X in the pump 10, for example, on 
the lever structure L, and the abutments 28 and 30, to further reduce 
operating noise. 
For substantially continuous contact between the plate member P and the 
electromagnet assembly 18, a center segment 64 of the shaft F on which the 
lever structure L is hinged translates between points N.sub.1 and N.sub.2. 
In particular, the center segment 64 translates from point N.sub.1 to 
N.sub.2 as the lever structure L moves from the release position to the 
compression position, and from N.sub.2 back to N.sub.1 as the lever 
structure L moves from the compression position back to the release 
position. To enable the center segment 64 to translate between the points 
N.sub.1 and N.sub.2, the shaft F is constructed of a resiliently flexible 
material, allowing ends 62 of the shaft F to remain fixedly attached to 
the side panels 34 while the center segment 64 substantially bows as 
necessary to accommodate movement of the lever structure L. 
FIG. 3 illustrates another embodiment of the present invention, where like 
elements are referenced with similar numerals. In this embodiment, the 
plate member P is position relatively perpendicular to the bar 46. 
Notwithstanding, the plate member P still moves between the release 
position (solid lines) and the compression position (broken lines), with 
the lever structure L compressing and releasing the center segment 26 with 
the striker S. Again, the lever structure L couples the lesser arcuate 
range R.sub.P of the plate member P with the greater arcuate range 
R.sub.ST of the striker S. Also, again, the edge portion E of the plate 
member P remains in contact with the electromagnet assembly 18 throughout 
the stroke, the shaft F translating between the points N.sub.1 and 
N.sub.2. 
It may be seen that the structure of the present invention may be readily 
incorporated in various embodiments to provide a pump 10. The various 
components and dimensions disclosed herein are merely exemplary and may 
not be to scale. Of course, various alternative techniques may be employed 
departing from those disclosed and suggested herein. For example, the 
plate member P may be variously joined with the lever structure L, 
provided that the plate member P moves between the angular-offset release 
position and the substantially parallel compression position. Also, the 
lever structure L may be variously configured, provided that it enables 
the plate member P to move within the lesser arcuate range R.sub.P and the 
striker S to move within the greater arcuate range R.sub.ST. Also, the 
means enabling the pivotal point of the lever structure L to translate may 
also be varied or assisted, for instance, by various tension members, such 
as springs or elastic bands. 
Consequently, it is to be understood that the scope hereof should be 
determined in accordance with the claims as set forth below.