[0001] This invention relates to devices for filling boxes, and particularly to devices
which are adapted to assist in properly filling a box with a loose particulate or
fibrous material, such as tobacco, by vibrating the box as the material is added to
it.
[0002] According to the invention there is provided a box filling device comprising a platform
including a conveyor, the platform being mounted on suspension springs, and means
for oscillating the platform on the springs, in a direction perpendicular to the direction
of movement of the conveyor.
[0003] Preferably, the oscillation is provided by means of an eccentric drive mechanism.
[0004] In a preferred arrangement of the invention, a pair of pneumatically operated mutually
opposed clamps are arranged to hold the box in position on the platform, whilst the
platform is oscillated.
[0005] One embodiment of the invention will now be described by way of example, with reference
to the accompanying drawings in which:
Figure 1 is a perspective view of a box filling device in accordance with the invention;
Figure 2 is a vertical cross section through a part of the device of Figure 1;
Figure 3 is a partially broken away end view of the device of Figure 1; and
Figure 4 is a side elevation of a vibrating drive arrangement for the device of Figure
1.
[0006] The device of Figure 1 is positioned in use so that the roller conveyor 2 is positioned
below a filling device (not shown) which is adapted to pour material (such as tobacco)
into the open top of a box 4 supported on the conveyor. In use, the box will be moved
onto the conveyor from another conveyor, and when it is correctly positioned on the
conveyor 2, the movement of the conveyor will automatically be stopped by means of
a control mechanism connected to photocell detectors 6.
[0007] Figure 1 also shows the drive cover 8 for the conveyor mechanism, and a pair of retractable
clamps 10 which are mounted on the device in such a way that they can be engaged against
opposite sides of the box, so as to hold it in position. The whole arrangement compising
the conveyor, the drive covers and the clamps 10, is mounted on vertical plate springs
so that it can be oscillated in the axial direction of the rollers of the conveyor
2, by means of a vibrator drive which is connected to one end of the unit, and which
is contained in the casing 14 shown in Figure 1.
[0008] Referring to Figures 2 and 3, the casing 8 encloses an electric drive motor 16 which
drives two of the rollers of the conveyor 2, via a chain 18 engaging with sprockets
20. The drive is in turn transmitted to the other rollers, by means of a further pair
of chains 22, 24, which similarly engage with sprockets on the ends of each of the
other rollers.
[0009] In the upper section of the casing 8, above the level of the motor 16, a pneumatic
ram 26 is mounted with its head 28 pivotally connected to the clamp 10, so as to enable
the clamp to be urged against the side of the box 4, as best seen in Figure 2. It
will be appreciated, that a similar pneumatic ram 26 is provided at the other side
of the box to operate the other clamping head 10.
[0010] The plate springs 27 are connected to a subframe 30, which also carries a dust collection
tray 12 and is in turn mounted on anti-vibration pads 32 fixed to the floor.
[0011] Referring now to Figure 4, it will be seen that the longitudinal vibration of the
apparatus is achieved by means of an eccentric drive device 34, driven by an electric
motor 36, both of which are rigidly mounted on the floor, on the framework 30 supported
by anti-vibration pads 38, and enclosed beneath the cover 14.
[0012] The connecting rod 40 of the eccentric drive mechanism 34 is pivotally connected
to one end of a frame member 42 supporting the conveyor mechanism, so that when the
motor 36 runs, the whole conveyor mechanism, including the rollers 2, the roller drives,
and of course the clamps 10, are vibrated along with the box 4.
[0013] The sequence of operations of the apparatus is as follows: firstly, with the unit
stationary, the clamp cylinders are retracted and the empty box is presented to the
roller conveyor which is actuated to load the box in position. Its correct positioning
is detected by the photo-electric cell 6.
[0014] The clamps 10 are then actuated at low pressure, and the motor 36 commences to run
to start the oscillations. As the box is filled, the clamp pressure is gradually increased
to a maximum, so as to compensate for the box loading. When the box is filled, the
oscillations cease, the clamps are retracted, and the roller conveyor is actuated
once again to off-load the box.
1. A device for ensuring uniform filling of a box with loose material such as tobacco,
comprising: a platform (2) for supporting the box (4) at a filling station, the platform
being mounted on suspension springs (27), and drive means (34, 36) for oscillating
the platform on the said springs.
2. A device according to claim 1 in which the said springs comprise vertically extending
metal plates whose upper ends are attached to fixed support members and whose lower
ends are attached to frame members (42) of the platform.
3. A device according to claim 1 in which the drive means for causing the oscillation
comprises a motor (36), an eccentric drive member (34) and a connecting rod (40) extending
between the drive member and one side of the platform.
4. A device according to claim 1, further comprising a roller conveyor incorporated
in said platform (2) for transporting the said box, into and away from the filling
station.
5. A device according to claim 4 in which the said platform includes means (6) for
sensing the position of the said box, and conveyor drive means arranged to move the
box into position under control of the said sensing means.
6. A device according to claim 1 further comprising a retractable clamp means (10)
adapted to grip the box on either side so as to hold it in position on the platform
whilst the platform is oscillated.
7. A device according to claim 6 further comprising pneumatic rams (26) for actuating
the clamps and control means adapted to progressively increase the pressure of the
rams as the box is filled, so as to compensate for the loading of the box.