Vacuum cleaner dust container having compressing means associated therewith

A vacuum cleaner having an air non-pervious body in the shape of a closed bellows in the suction chamber thereof with one end of the bellows bearing against the dust container, and the other end bearing against a partition separating the suction chamber from a positive pressure chamber housing the motor-fan unit. The bellows communicates with the pressure chamber through a conduit so that the bellows can be brought into communication with the positive pressure side of the fan so that the bellows expands and compresses said dust container and its contents, and thus increases the filling capacity of the dust container. The running costs of operating a vacuum cleaner is thus substantially reduced.

The invention relates to a vacuum cleaner having compressing means for a 
dust container associated therewith. The compressing means is a 
non-pervious body to air arranged in the suction chamber and is 
compressible due to changed pressure conditions therein. 
It is known to compress a dust container for obtaining a higher filling 
factor for the same when a vacuum cleaner is operative. This arrangement 
makes is possible to continue to use dust containers in vacuum cleaners 
for their optimum utilization. Thus, two frequent changes of dust 
containers are eliminated. This arrangement has a further advantage of 
decreasing the running cost of vacuum cleaners. In a known arrangement 
which is set forth in applicant's copending patent application Ser. No. 
86,353, filed on Oct. 19, 1979, and now U.S. Pat. No. 4,277,265, issued on 
July 7, 1981 a dust container is shown and described which together with 
its contents is compressible by means of an air non-pervious body 
surrounding the dust container. In this arrangement the outside of the 
non-pervious body is temporarily exposed to atmospheric pressure whereby 
the dust container is compressed due to the negative pressure prevailing 
inside the dust container. 
Through experimentation it has been proved that the known arrangement can 
be improved further, and the filling capacity of the dust container can be 
increased considerably over the limit known heretofore. This desirable 
result is essentially achieved in that the air non-pervious body has the 
shape of a closed bellows, the inner space of which can be brought into 
communication with the positive pressure of the motor fan unit.

The housing defining a part of the vacuum cleaner is referred to generally 
by the reference numeral 10, and contains a suction chamber 11 having an 
inlet opening 12 for dust-laden air and a pressure chamber 13 with an 
outlet opening 14. A partition 16 separates the suction chamber 11 from 
the pressure chamber 13. A dust container 15 is arranged in the suction 
chamber 11, and an air non-pervious body in the shape of a closed bellows 
17 made, for example of rubber, plastic or another suitable material is 
also located therein. The bellows 17 bears with one of its ends 18 against 
the partition 16 and with its other end 19 against the dust container 15. 
A motor-fan unit 20 for transport of air from the inlet opening 12 through 
the dust container 15 is positioned in the pressure chamber 13. The dust 
particles are separated out and the air then moves through the suction 
opening 21 of the motor-fan unit to the pressure chamber 13 where the air 
departs from the vacuum cleaner through the outlet opening 14 to the 
surrounding atmosphere. 
The outlet opening 14 is closable during the compressing stage by means of 
a flap 22, actuated by a member sensing the pressure drop over the dust 
container wall, said member having the shape of a piston 25 movable within 
a cylinder 23 against the force of a compression spring 24. A rod 26 
connects the front end of the piston with the flap 22 through a lever 27, 
and permits a movement of the flap from a position closing the outlet 
opening (FIG. 2) to a position in which the outlet opening is open (FIG. 
1). In the open position, one end of the flap 22 closes an air conduit 28 
passing through the partition 16 and connecting the pressure chamber 13 
with the inner space of the bellows. A seal 29 arranged on the flap 
ensures an air tight fit between the flap and the mouth of the air conduit 
28. 
A hole 30, the cross flow area of which is considerably below the inner 
area of the air conduit 28 is positioned in the central portion of a 
diaphragm 31 at the end wall 18 of the bellows directed towards wall 33. 
The diaphragm is arranged at a distance from the suction opening 21 of the 
motor-fan unit 20 and is attached to a ring-shaped portion 32 of an inner 
wall 33 by means of its peripheral part. The wall 33 having axial parts 34 
forms an enclosure 35 for taking up the bellows 17 during the running 
stage, as evident from FIG. 1. 
The device functions in the following manner: while using the vacuum 
cleaner, air is taken in through the inlet opening 12 and sucked through 
the dust container 15 where it is cleaned and delivered by the motor-fan 
unit 20 through the outlet opening 14 to the surrounding atmosphere, as 
seen in FIG. 1. When a certain amount of clogging of the inside of the 
dust container has taken place, and the pressure drop over the dust 
container wall has increased sufficiently, i.e., the negative pressure on 
the outside of the dust container is sufficiently high, the negative 
pressure prevailing on the outside of the dust container is through 
conduit 36 transmitted to the inside of the piston 25 which then moves 
against the force of spring 24 from the position shown in FIG. 1 to the 
second position shown in FIG. 2. This movement is transmitted by means of 
a rod 26 and lever 27 to the flap 22, which pivots to the position 
illustrated in FIG. 2, and closes the outlet opening 14. 
Positive pressure is created in the pressure chamber 13 and air flows 
through air conduit 28 into the bellows 17, which quickly expands to the 
position shown in FIG. 2 and compresses the dust container 15. However, 
before that, the diaphragm 31 has bulged out as seen in FIG. 2, due to the 
positive pressure prevailing in the bellows, and has sealed the suction 
opening 21 of the motor-fan unit. 
After the occurrence of the foregoing, the air pressure on the outside of 
the dust container 15 decreases, which is transmitted through conduit 36 
to the inside of piston 25, and the piston moves to its initial position 
shown in FIG. 1. The flap 22 then opens the outlet opening 14, and the 
bellows is evacuated through hole 30, while the diaphragm 31 opens the 
suction opening of the motor-fan unit and the bellows returns to its 
inactive position within the enclosure 35, as seen in FIG. 1. 
During the compression function dust has been freed from the walls of the 
dust container 15 and compressed, so that further dust can be supplied to 
the dust container and the filling factor of the dust container has been 
increased in this manner. In actuality, there is about a doubling of the 
filling factor due to the compressing mode as compared to a conventional 
apparatus without compression. It should be evident that during vacuum 
cleaning the compression mode can be repeated several times, and this can 
be done manually or automatically, as shown in the present embodiment, 
which is not intended to limit the invention in any respect. Several 
modifications are thus conceivable within the spirit and scope of the 
invention, as defined in the following claims. Thus, e.g. the closing of 
the outlet opening 14, i.e., the initiation of the compression, can be 
achieved by the aid of magnets, or electronically. 
The arrangement according to the present invention is superior to the prior 
art arrangement as described hereinbefore because the whole available 
difference between the pressure and suction sides of the fan can be 
utilized instead of using only the essentially lower difference between 
the atmospheric pressure and the negative pressure of the vacuum cleaner.