[0001] The subject of the invention is a device for unscrewing and removing screws, cooperating
with an automatic or semi-automatic screwdriver.
[0002] A device for removing and storing fastening nuts is known from the US patent description
US5640889.
[0003] There are also known automatic and semi-automatic applications of electric or pneumatic
screwdrivers, in which screws can be both screwed in and unscrewed. However, when
the screw is unscrewed therewith, it remains in the hole or is attached to the screwdriver
tip by the force of the tip rubbing against the shapes of the screwdriver, or by the
magnetic attraction of the screw and the tip. This blocks the possibility of unscrewing
another screw. To unscrew another screw, the screw has to be removed from the screwdriver
tip, and in the case of a screw remaining in the hole, there is a need to pull it
out of the hole.
[0004] A device for unscrewing and removing screws according to the invention includes a
screwdriver and a special suction head for removing unscrewed screws, the suction
head being provided with three channels: a channel for guiding and positioning the
screwdriver on the screw, a channel for sucking in (introducing) the screw and a channel
for sucking off (removing) the screw from the suction head. The screw sucking in channel
is connected to the screw sucking off channel via a closing wall positioned at an
angle not smaller than 90° in relation to the screw sucking in channel. Preferably,
the closing wall is cylindrical.
[0005] The solution according to the invention allows removal by sucking off of each screw
immediately after it is unscrewed by an automatic screwdriver. Removing of the unscrewed
screws from the working area and machine parts can be applied with automatic and semi-automatic
screwdrivers, as well as with manual screwdrivers. Removing of the unscrewed screws
is also important in semi-automatic applications, i.e. using screwdrivers manually
controlled by operators during service work and dismantling of equipment or waste.
In this application, removing screws allows to maintain tidiness and cleanliness,
and thus work safety. In case of service work, it is often a practice to replace removed
screws with new ones, so automatic removal of the screws after unscrewing them eliminates
the risk of reusing them. An automatic screwdriver mounted, e.g. on a cartesian machine,
spring balancer, reaction arm, cobot, or other robot, in robotic disassembly applications,
automatically unscrews the screws and, thanks to the invention, they are removed from
the working area, which enables continuous and failure-free operation and functioning
of the automatic or robotic line. Additionally, in this application, the removed screws
go to a designated container and may be separated, e.g. in terms of magnetic or other
properties. This contributes to obtaining homogeneous material for reuse, e.g. raw
material recycling of stainless or ferrous screws by magnetic properties.
[0006] The second function of the device according to the invention, apart from removing
screws, is the ability to replace the screwdriver tip after lifting it to the upper
position, above the head. This is important in robotic disassembly technology when
it is necessary to replace the tip due to unscrewing a different type of screw, e.g.
change from Phillips to Torx or to a different size, from PH01 to PH00, from TX06
to TX08, etc.
[0007] The subject of the invention is shown in an embodiment in a cross-sectional drawing,
in which Fig. 1 shows the position of the screwdriver tip ready for unscrewing the
screw and the location of the screw during unscrewing; Fig. 2 shows the moment of
raised position of the screwdriver tip enabling its replacement and removal by suction
of the released screw after unscrewing it.
[0008] The device for unscrewing and removing screws comprises a screwdriver
1 and a suction head
2. There are three channels placed in the suction head
2: a guiding channel
3 that guides the screwdriver
1 to the head of the screw
4, a sucking in channel
5 that brings the screw
4 to the closing wall
6 that connects to the sucking off channel
7. The closing wall
6, positioned at an angle not smaller than 90° in relation to the channel
5, ensures the release of the screw
4 from the screwdriver
1 and the free movement of the screw
4 in the sucking off channel
7. The direction of air movement caused by the suction negative pressure is illustrated
by arrows
8. In the preferred embodiment, the wall
6 is cylindrical, but the invention is not limited to this example - the wall can also
be flat.
[0009] The tip of the screwdriver
1 together with the suction head
2 is positioned to the head of the screw
4. After starting the operation of the screwdriver
1, it rotates the tip that unscrews the screw
4. The screw
4, during unscrewing from the hole, rises and pushes the tip of the screwdriver
1 up, simultaneously entering the channel
5 sucking in the screw
4 after it is unscrewed. While the screwdriver
1 is operating, the negative pressure
8 sucking out air from the environment is turned on, providing a suction force and
pulling the screw
4 into the sucking channel
5. When the screw
4 is fully unscrewed, the screwdriver
1 is withdrawn from the head
2 upwards beyond the head
2. The screw
4 held at screwdriwer's tip
1 by means of negative pressure
8, magnetic forces or friction is pulled into the channel
5 which ends with wall
6, here it is torn off from the tip of the screwdriver
1 and freely sucked off into the channel
7 together with the air sucked in by the vacuum pump in the direction of operation
of the negative pressure
8. The screw released from the tip of the screwdriver
1 and retained on the wall
6 can now move freely in the channel
7 along with the air stream caused by the negative pressure
8 or forced into it by blowing of compressed air into the channel
7. Through the channel
7, the screw
4 is transported to the screws container (not shown), in which the air velocity slows
down and the screw
7 falls freely into the screws container. After the tip of the screwdriver
1 reaches the upper position, the tip of the screwdriver is reinserted into the head
2 and the device is again ready to unscrew and remove another screw. Moreover, the
tip of the screwdriver
1 withdrawn from the suction head
2, in its upper position allows it to be replaced. The operating sequence is repeated
for each screw.
