The present invention relates to a stopping device for a transport
trolley, more particularly a stopping device for a transport trolley driven by
a continuously rotating axle which is positioned according to the movement direction
of such trolley.
More particularly, the present invention has as an object a stopping
device for transport trolleys whereby the transport trolley is moved along guidances
or rails, preferably on running wheels, and whereby under this transport trolley,
driving wheels are provided which cooperate with said continuously rotating axle
in order to move the transport trolley along said guidances or rails.
The stopping device has as a function either to let the transport
trolley pass at a maximum speed when a stop of the transport trolley is not necessary
(stopper completely drawn back); or to slow down such transport trolley and to
bring it gradually to a complete standstill (stopper completely drawn out), when
products placed upon such transport trolley have to be processed or similar; after
standstill, to let the transport trolley gradually accelerate up to maximum speed
(stopper partially drawn back).
The maximum speed reached by such transport trolley will be obtained
when said driving wheels provided under such trolley are placed at an angle of
45° in respect to the longitudinal direction of said driving axle, whereas a complete
standstill of the transport trolley in respect to the aforementioned rails will
be achieved when these driving wheels form an angle of 90° with said driving axle
and the speed of the transport trolley can be altered progressively between the
standstill of the transport trolley and the maximum speed thereof by placing said
driving wheels at other angles.
A great disadvantage of known stopping devices consists in that,
when a transport trolley, is set moving again from a standstill, this is always
accompanied by a sudden acceleration from 0 up to the maximum speed of the transport
chain, as a result of which such transport trolley is subject to relatively large
shocks, which, in certain cases, is not desired or allowed.
Therefore, the stopping device according to the invention aims at
placing said driving wheels provided under such transport trolley, which are in
contact with said driving axle, at the suitable moment at a suitable angle in
respect to this driving axle, in order to be able to obtain a desired speed and
to have the deceleration or acceleration of the transport trolley into or from
a standstill run progressively.
This stopping device for a transport trolley which can be moved along
guidances or rails and whereby the transport trolley is provided with driving wheels
which cooperate with a rotating axle and which, by means of a lever with a contact
wheel, can be set at different angles in respect to said driving axle, has as a
characteristic that this stopping device consists of at least a lever with an
ascending edge and a descending lateral edge, prolonged by an acceleration lever,
the transition of which is formed by a tip, and a hydraulic, pneumatic or electric
drive which can position said levers in three positions, namely, with said tip
outside the path of said contact wheel and out of contact with the levers; with
lever and tip entirely in the path of the contact wheel; and with the tip outside
of the path of the contact wheel, however, with the contact wheel in contact with
the acceleration lever.
With the intention of better showing the characteristics of the present
invention, hereafter, by way of example without any limitative character, a preferred
form of embodiment of a stopping device according to the invention is described,
with reference to the accompanying drawings, wherein:
- figure 1 represents a perspective view of a stopping device according to the
invention, applied in a transport trolley driven by a driving axle;
- figure 2 represents a schematic top view of figure 1;
- figure 3 represents a view similar to that of figure 2, but for another position
of the transport trolley;
- figure 4, at a larger scale, represents the stopping device as indicated by
F4 in figure 3;
- figure 5, at a larger scale, represents a schematic view according to arrow
F5 in figure 4;
- figures 6 and 7 are similar to that of figure 4, but with the stopping device
in two other positions.
In figure 1, a stopping device 1 according to the invention is represented
which is situated between two rails, 2-3, respectively, along which a transport
trolley 4 can move by means of running wheels 5 and whereby between these rails
2-3 and parallel thereto, a driving axle 6 is provided which is driven continuously.
Such transport trolley 4 further is provided at its underside with
a number of driving wheels 7 which are freely rotatable around a pivot 8 which
in its turn is fixed in a support 9.
The support 9, at its free extremity, is fixed freely hingeable,
by means of a pivot 10, to a rod 11 which is common for the different supports
9 of the different driving wheels 7.
Further, a rod 12 is connected freely hingeable to the rod 11, for
example, in one of the pivots 10, whereby this rod 12 at its other extremity, by
means of a pivot 13, is connected freely hingeable to a lever 14 which can pivot
around a pivot 15 which is fixed at the underside of the transport trolley 4 in
a suitable manner.
The second free extremity of the lever 14 is provided, by means of
a pivot 16, with a freely rotatable contact wheel 17, whereas between the lever
14 and the bottom wall of the transport trolley 4, a spring 18 is provided which
always aims at moving the lever 14 in contact with a stop 19.
The stopping device 1 according to the invention, the intention of
which it is to let the transport trolley 4 either pass freely or to let the transport
trolley 4 decelerate and stop completely; or to let the transport trolley accelerate
from a complete standstill, consists of a first lever 20 (gradual deceleration
and complete stop) which at one extremity is fixed freely hingeable at a pivot
21 which in its turn is fixed in a fixed support 22, whereas the second extremity
to the lever 20, by means of a pivot 23, is connected freely hingeable to a second
lever or acceleration lever 24 (gradual acceleration up to maximum speed) which,
at its second extremity, by means of a pivot 25, is connected freely hingeable
to a rod 26 which in its turn is connected freely hingeable, by means of a pivot
27, to a fixed support 28.
Further, the first part 30 of a bent lever 31 is connected to the
first lever 20 by means of a pivot 29, whereby the second part 32 of said bent
lever 31 is connected freely hingeable to, on one hand, said first part 30, by
means of a pivot 33, and, on the other hand, to a fixed support 34, by means of
a pivot 35.
On the pivot 33, also the free extremity of the piston rod 36 of
an hydraulic or pneumatic cylinder 37 is provided, the body of said cylinder being
connected freely hingeable to a fixed support 39 by means of a pivot 38, whereby
said cylinder 37 is positioned almost parallel to the lever 20. Of course, the
cylinder 37 can also be formed by an electric drive.
The functioning of the stopping device 1 according to the invention
is very simple and as follows.
In the position as represented in figure 4, the driving wheels 7
are in the position of maximum speed, namely, at an angle of 45 degrees in respect
to the driving axle 6 and the stopping device 1 is in drawn-back position, such
that the tip T of the first lever 20 is outside the path of the contact wheel
In this position, the transport trolley 4 thus could pass freely,
without having its speed slowed down in which manner whatsoever.
In figure 6 is represented that the lever 20 is placed completely
in the path of the contact wheel 17, whereby the driving wheels 7 are turned over
90 degrees, such that the transport trolley 4 comes to a complete standstill and
is kept at such standstill up to the moment when the lever 20 is partially drawn
back by means of the cylinder 37.
As the contact wheel 17 at the height of the stopping device 1 first
will come into contact with the ascending edge 40 of the first lever 20, as a result
of which the driving wheels 7 are placed at an angle in respect to the driving
axle 6 which is larger than 45 degrees, the transport trolley 4 will be slowed
down gradually up to the point when the contact wheel 17 touches the tip T.
When lever 20, by means of cylinder 37, subsequently is partially
drawn back, the contact wheel 17, under the influence of spring 18, will gradually
move over the descending edge 41 of lever 20 and subsequently over the acceleration
edge of lever 24, in such a manner that the driving wheels 7 are gradually brought
from their zero position into a position of 45°, such that the transport trolley
4 gradually accelerates.
It is obvious that in this manner, a stopping device 1 for a transport
trolley 4 is obtained which allows to subject the transport trolley 4 to three
different working regimes, namely, full speed; gradual deceleration up to complete
standstill; and gradual acceleration from complete standstill.
The present invention is in no way limited to the embodiment described
heretofore, but can be realized in a variety of forms and dimensions without leaving
the scope of the invention.