Sterile water collector

A sterile water collector of the type comprising a sample device (11) and a sample receptacle (1), and in which the sample receptacle is activated by means of a dropping plummit, which brings about opening of an inlet to the evacuated sample receptacle, which consists of a flexible wall structure (6) located between two rigid end bodies (2,3), whereby the rigid end bodies by means of a load are arranged to be pulled in a direction away from each other a certain distance when the sample device (11) is activated, whereby the sample water is sucked into the receptacle.

BACKGROUND OF THE INVENTION 
The present invention relates to a sterile water collector of the type 
comprising a sampling device and a sample receptacle arranged to be 
activated by external actuation, whereby an inlet to the evacuated sample 
receptacle is opened. 
Sampling of water for bacteriological tests necessiates that the samples 
can be collected without being contaminated by foreign bacteria. Such 
sampling is used e.g. at bacteriological control of bathing and drinking 
water or for determination of the number and activity of bacteria in 
different water systems. Different water collectors have been designed for 
such purposes, but none of those conventional water collectors fulfil all 
requirements which are made of a practically manageable, sterile water 
collector. Those requirements are: 
Sampling device and sample receptacle shall be separable units. It is 
desirable for economic reasons that several sample receptacles can be used 
on the same sampling device, as the sampling device for a sterile water 
collector requires some technical contrivances. The manageability of the 
sample increases further if the sample receptacle can be separated from 
the sampling device when recovered from the water. 
The water collector shall be usable together with a wire from a winch as 
well as with a separate rope. A wire from a ship is commonly used, but 
sampling from jettys, in wells and the like necessiates that the collector 
can be used on a single rope. 
Fitting and maneuvering of the water collector shall be realizable with 
simple hand grips. Such factors as rough seas, coldness and the use of 
clumsy gloves must not hamper the sampling work. 
The sample shall be collected so far from the collector that there is no 
risk for contamination from the wire and sampling device. This is a 
requirement, as bacteria may accompany the collector and wire down through 
the water and then contaminate the sample, and these bacteria are not 
representative for the water at the sampling level if the sample is 
collected immediately adjacent the collector or wire. 
It shall be possible to use several collectors on the same wire 
simultaneously, as samples are often desired from several levels at the 
same time. When the collector is activated by means of a plummet which 
runs along the wire, a second plummet is to start from a level below or 
above the collector just activated in order to activate the next collector 
etc. 
The inlet for sample water shall be open only during the time for 
collecting the sample. If the inlet is open during the entire time of 
submersion or recovery the risk for contamination is of course increased. 
Sampling device and receptacle shall be able to operate without problems on 
large depths at high pressures. 
It shall be possible to sterilize the sample receptacle, preferably by 
means of an autoclave, which can easily be accomplished at sea. 
The sample receptacle shall be a cheap disposable article or it shall be 
reusable after machine dish-washing. 
The water collector shall be manufacturable for sample volumes between 
about 0.3 liters and 10 liters without the function being altered. 
Sampling device and receptacle must withstand rough treatment. 
For certain tests it must be possible to make the sample receptacle 
impermeable to light. 
The collector shall withstand low temperatures. The temperature of the 
surface water of the sea can, during the winter, be about -3.degree. C. 
and the air temperature can be considerably lower. The collector should 
not become brittle at such temperatures. 
Earlier sterile water collectors use as activating member a plummit, which 
is dropped along the carrying wire and which when reaching the collector 
by means of its kinetic energy starts the sampling. 
One of these older water collectors is the ZoBell collector, which operates 
with a sterile and evacuated glass bottle to which is connected a rubber 
tube, which at one of its ends is closed by means of a glass tube. When 
the plummit is dropped and hits the glass tube this is broken and the 
rubber tube is, by means of its inherent flexibility, swung out from the 
sample receptacle. Water flows into the bottle and fills it. At the same 
time a second plummit is activated and dropped from the activated 
collector and is allowed to sink to the next collector etc. Advantages of 
this ZoBell collector are that it is easy to handle and that it collects 
the sample some distance away from the collector. Its drawbacks are that 
it can not operate on depths larger than 50-100 meters, and that the 
sample receptacle is open after activation. 
The water collector most frequently used in microbiology is the 
Niskin-collector, in which a falling plummit releases a knife, which cuts 
a hole in a sterile plastic bag threaded over the spring-loaded wings of 
the collector. A rubber tube for collecting the sample then swings out a 
short distance from the collector, at the same time as the spring force 
causes the wings to be filled out, whereby the bag is filled. The bag is 
thereupon automatically closed by a closing mechanism. This collector has 
the advantages that it is closed immediately after the sampling, it can be 
used at great depths and large volumes can be collected. Its drawbacks are 
that use of the collector requires several careful hand grips made 
simultaneously which is time-wasting and difficult. The plastic bag is 
furthermore disposable and the cost for each bag is high, about 10 to 15 
Swedish Krona, and at the same time as the bag is frail whereby it can 
easily leak at handling. Furthermore the knife which cuts off the plastic 
bag can contaminate the contents, and finally bigger collectors of this 
type are very difficult to handle. 
SUMMARY OF THE PURPOSE AND MOST ESSENTIAL FEATURES OF THE INVENTION 
The purpose of the invention is to provide a practically usable sterile 
water collector of the type initially described, which fulfils all 
requirements set out hereabove. This has been achieved thereby that the 
water collector has been given the following characteristics; the sample 
receptacle consists of a flexible wall structure located between two rigid 
end bodies, and the rigid end bodies are arranged at activation of the 
sampling device by means of an external force to be displaced in a 
direction away from each other a certain distance, whereby sample water is 
sucked into the receptacle.

DESCRIPTION OF PREFERRED EMBODIMENTS 
The water collector according to the invention incorporates a sampling 
device 11 and a sample receptacle 1, shown in FIG. 1 in inactive, 
evacuated position, whereas FIG. 2 shows the sample receptacle 1 in 
activated, water-filled position. 
The sample receptacle consists of an upper circular gable 2, a lower 
circular gable 3, upper and lower clamping rings 4,5 and a cylindrical 
plastic bag or hose 6. The upper gable 2 is provided with a central inlet 
7 designed with a tubular socket 8 projecting from one side thereof and 
intended for connection of a tube 20. The through-inlet 7 is conically 
decreasing in a direction towards the socket 8. 
The lower gable 3 is provided with a column 9 projecting from one side 
thereof and terminating in a tapering portion 10, having the same taper as 
the inlet 7. 
The clamping rings 4,5 can be designed in different ways but the important 
thing is that they can be used for attaching one end of the plastic bag or 
hose 6 to the gables 2 and 3 respectively. It must be possible to 
sterilize the material used in the gables and in the clamping rings in an 
autoclave and they should withstand machine dish-washing. 
The plastic hose 6 is commercially available at a price of about 1 
SEK(Swedish Crown)/meter, and is in medical care technology referred to as 
"autoclave plastics". 
At the end of the rubber tube 20 facing away from the socket 8 there is, in 
this embodiment, arranged a glass tube 30, the free end of which is 
closed, whereby also the sample receptacle 1 is closed. 
Prior to the sampling the plastic bag 6 is evacuated via the rubber tube 
20, which is thereupon closed by means of said glass tube. In this 
position the sample receptacle has the appearance shown in FIG. 1. The 
sample receptacle is then ready for use after treatment in an autoclave. 
All parts of the sample receptacle except for the glass tube, which is 
broken later, can be dish-washed and reused, but the plastic bag 6 should 
for practical reasons be considered as disposable material. 
The plastic bag 6 for the sample receptacle can be cut off from a roller 
into desirable lengths depending on desired sample volume, but the 
relation between height and width is important as too large a ratio means 
that the bag 6 when activated will not unfold entirely and too small a 
ratio means that the sample receptacle can not be entirely evacuated. The 
design of the tapering column portion 10 and the tapering central inlet 7 
provides a nonreturn valve which is essential for the function of the 
collector as it will prevent the plastic hose 6 from creeping into the 
sample tube when the sample receptacle is subjected to pressure. 
In FIG. 3 is shown one embodiment of a sample device 11 with the sample 
receptacle 1 in inactive position. The sample device comprises a stand 12, 
and the upper gable of the sample receptacle can be attached to the upper 
part thereof in a bayonet mount 13 or the like. The lower gable 3 of the 
sample receptacle is provided with a coupling dowel 22 with a pressure 
spring 23 threaded thereon. 
The coupling dowel can be inserted in a coupling 14, provided with coupling 
shanks 15 by means of which the sample receptacle is rigidly attached to 
the coupling. A mounting tube 16 extends from the coupling 14 to a 
releasing device 17 by means of which the mounting tube 16 can be 
displaced out through an opening 18 in the bottom plate 19 of the sample 
device. The coupling 14 is spring loaded by means of elastic members 24, 
which press the lower end of the tube 16 against two rails 25 which are 
displaceable laterally by means of an actuation mechanism 26. This 
mechanism consists of a conical actuation member, the point of which is 
directed against the space between the laterally displaceable rails. This 
member is, via a rod 27, connected to a breaking mechanism 28. This later 
mechanism comprises a retainer 29 for a glass tube 30 and a lever 31, 
which by means of a spring and the rod 27 are kept in the position shown 
in FIG. 3. The lever 31 can be pushed down in the direction of the arrow 
by means of a weight, e.g. a plummit, whereby the glass tube 30 is crushed 
(broken) and the releasing device 17 is opened and the coupling with the 
lower gable of the sample receptacle is displaced downwards due to 
actuation by the elastic members 24. 
When the coupling has moved to a level in the vicinity of its downmost 
position it will hit a lever 32, which via a spring loaded push rod 33 
lifts a lock bolt for engagement with a spring loaded locking plunger 34, 
which is designed so that it exerts a pressure on the tube 20 which is 
inserted through a hole 35 in the locking device 36, whereby the tube is 
compressed so the communication with the sample receptacle is interrupted. 
The sampling device is preferably suspended from a wire which is preferably 
attached thereto in such a manner that a plummit can be dropped down along 
it and hit the lever 31. 
For activation of the sampling device at the desired depth, a not shown 
plummit is thus dropped and will activate the breaking mechanism 28, 
whereby the glass tube 30 is crushed. The sample tube 20 then will swing 
out from the sampling device due to its inherent elasticity, at the same 
time as the releasing device is activated and the lower gable of the 
sample receptacle 1 is filled with water. At the time the receptacle is 
full the coupling 14 reaches its bottom position and it will then release 
the closing mechanism 36 which pinches around the sampling tube and closes 
it. 
When the water collector has been recovered the tube is provided with a 
tube clasp and the closing mechanism can be disengaged, whereupon the 
sample receptacle 1 can be released from the bayonet mount 13, and the 
sample device is ready to be provided with a new sample receptacle for 
renewed use. 
FIG. 4 shows in a side view a modified embodiment of a water collector 
according to the invention. Corresponding details have been given the same 
reference numerals as those in the embodiment according to FIGS. 1 to 3. 
The sample receptacle 1 is the same as that used in the previous 
embodiment, but shown in folded out position, and it is attached to a 
sampling device 41, which has means 13 for connection of the upper gable 
of the receptacle and a coupling 14 corresponding to that of the earlier 
embodiment. The main difference between this embodiment and that shown in 
FIG. 3 is that the rubber tube 20 at its end remote from the receptacle in 
inactive position is closed by being slipped over a sealingly fitting peg 
42, which is clearly shown in the detail view of FIG. 5 showing the upper 
part of the device with some parts in section. This peg 42 is pivotably 
connected about a shaft 43 fitted on a lever 44, which is arranged to 
extend over the path of the plummit 45. The plummit 45, when dropped along 
the wire 46, will hit the lever and move this downwards, whereby the peg 
42 simultaneously will move downwards between two wall parts 47, 48. The 
passage between these walls is at least in the upper part so small that 
the peg can just pass through and the rubber tube 20 then will be pushed 
off the peg when this is moved down. The tube is thereby released and can 
due to its inherent flexibility swing out from the side of the collector. 
The coupling 14, and the actuation mechanism 26 are simultaneously 
activated and begin to pull the lower gable of the receptacle 1 downwards 
whereby water is sucked in through tube 20. The tube 20 is closed off by 
the locking mechanism 36 in the same manner as earlier mentioned as soon 
as the receptacle is filled, i.e. as soon as the coupling has reached its 
lowermost position. The glass tube used for closing the rubber tube 20 in 
the previous embodiment is in this embodiment replaced by the peg 42, 
which does not have to be crushed in order to open the communication 
between the ambient water and the interior of the receptacle. The function 
is however in all other aspects similar to that of the earlier described 
embodiment. 
The disclosed invention provides a collector at a very low price, which 
fulfils all the above listed requirements, and the "concertina folding 
principle" used for the sampling has proven itself to function in a 
faultless manner.