Device for grasping and transporting objects

A device for grasping and transporting objects, wherein the device has a plurality of plate-shaped supports combined into a rotating conveyer chain. Each support has at least one suction opening on a transport side of the support, which is connected over at least a portion of a transport path. A fixed suction conduit can be sealed airtight against the atmosphere. Each suction opening is in communication with a supply of suction air or compressed air. The supports are adjustably guided in guide rails which receive edges of the supports that extend parallel to a direction of conveyance. The suction openings are formed as elongated holes within the supports. The elongated holes are aligned in the direction of conveyance. The elongated holes are sealingly connected on a side facing away from the transport side with a fixed suction conduit that extends along the transport path. The suction conduit is formed as a conduit rail and encloses the elongated holes with front faces of the two side legs. The side legs are supported on either the supports or connecting strips which are fastened on the supports. Enlarged holes correspond to the elongated holes and make a transition into the elongated holes.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a device for grasping and transporting objects, 
having a number of plate-shaped supports combined into a rotating conveyor 
chain, wherein each support has at least one suction opening on its 
transport side, which is connected over at least a portion of the 
transport path with a fixed suction conduit that can be sealed airtight 
against the atmosphere and that leads to a supply point for suction air or 
compressed air. The supports are adjustably guided in guide rails which 
receive the edges of the supports extending parallel to the direction of 
conveyance. 
2. Description of Prior Art 
A device of this type is known from German Patent DE 37 01 564 C1. In this 
device it is only possible to dispose bores of small diameter because of 
the lesser thickness of the supports and the structural height of the 
guide rails connected therewith. Therefore the suction plates have only 
little suction force and thus holding ability. For this reason the 
conventional device is particularly suited for grasping and transporting 
light objects with smooth surfaces. 
SUMMARY OF THE INVENTION 
It is one object of this invention to provide a device of the above 
mentioned type wherein it is also possible to grasp and transport heavier 
objects which do not have smooth surfaces. 
In accordance with this invention, the above object is achieved with 
suction openings that are cut into supports in the form of holes. The 
holes in the supports are sealingly connected on the side facing away from 
the transport side with the fixed suction conduit extending along the 
transport path. 
In spite of the small thickness of the support, the hole in the support can 
have a considerably large surface, so that it is possible to obtain a 
greater holding force by suction air, which is distributed over a large 
surface of the object and therefore does not require an absolutely tight 
sealing of the hole. 
To be able, nevertheless, to keep the width of the suction conduit small, 
in a further embodiment of this invention, the holes in the supports are 
embodied as elongated holes aligned in a direction of conveyance. 
So that no leaks occur at the places where the supports meet, in a further 
embodiment of this invention, the supports are sealed with respect to each 
other at the edges extending crosswise to the direction of conveyance with 
sealing elements, which extend at least over the area of the suction 
conduit disposed above the holes. 
In accordance with yet a further embodiment according to this invention, it 
is possible to enlarge the suction surfaces of the support in a simple 
manner since the holes of the supports make a transition into enlargements 
on the transport side. 
If the transport side of the support has an open-pored suction plate, which 
covers the hole or its enlargement, the suction surface is resilient so 
that it can be adapted to irregularities of the grasped and held object. 
A further embodiment of this invention provides that the side of the 
support facing the transport side has a connecting strip extending in the 
direction of conveyance, provided with an opening that corresponds to a 
hole of the supports and which makes a transition into it. These 
connecting strips are provided on a front extending crosswise to the 
direction of conveyance with the sealing element which seals in the 
direction toward the connecting strip of the adjacent support. 
The material of the connecting strips can be adapted to the material for 
the suction conduit in such a way that a tight connection with little 
friction is obtained. In addition, the connecting strips connected with 
the supports can be replaced if leaks occur after prolonged use. The 
conveyor chain with the supports does not need to be dismantled for this 
operation. 
The connection of the supports with a conveyor chain is simplified in that 
the side of the support facing away from the transport side has a pair of 
chain connecting elements on both sides of the connecting strips. These 
chain connecting elements are connected with each other across the joints 
of the supports with chain links. 
If at least one of the guide rails has a conduit extending over the length 
of the transport path and has a conduit connection, which is completed and 
sealed by the supports guided in the guide rails, at least one bore starts 
at the front of the support guided in the guide rail and continues into 
connecting conduits extending to the transport side, and the connecting 
conduits are connected with suction plates, it is then also possible to 
equip the support selectively with suction plates, too, in order to be 
able to grasp and transport light objects with smooth surfaces. For 
sealing the conduit in the guide rail the supports can be sealed in the 
area of the guide rails with sealing elements. 
Operation of the device can also be accomplished with compressed air if the 
bores in the supports extend beyond the connecting conduits as far as the 
oppositely located front, the conduit connection is charged with 
compressed air and a Venturi nozzle is inserted into the bore of the 
support from the direction of the connecting conduits. 
The sealing of the suction conduit on the side of the support facing away 
from the transport side is improved if the suction conduit is formed by a 
U-shaped rail which is closed off at its ends and is resiliently supported 
by the front ends of its lateral legs on the supports or on the connecting 
strips fastened on the supports.

DESCRIPTION OF PREFERRED EMBODIMENTS 
The cross section taken through the device shown in FIG. 1 extends 
crosswise to the direction of conveyance of the conveyor chain, wherein 
the transport side of the supports 10 is downwardly oriented. However, the 
device can also be used if rotated by 180.degree. with the transport side 
oriented toward the top. In the first case, the grasped objects are 
transported hanging and in the second case the grasped objects are 
transported lying on top. The conveyor chain can also be used so that it 
is inclined upward, downward or even aligned vertically. This only depends 
on the weight of the objects and the suction force provided by the central 
supply device. 
As shown in the cross section of FIG. 1, the edge areas of the plate-shaped 
supports 10 extending parallel to the direction of conveyance are 
adjustably guided in U-shaped guide rails 30 at least over the transport 
path provided, wherein the supports 10 are moved, if possible without a 
large amount of play, in the receptacles of the guide rails 30. Holes 11, 
shown as elongated holes are cut into the supports 10 and form a suction 
opening with a large cross section on the transport side. The elongated 
holes 11 are aligned in the direction of conveyance and continue into the 
holes 21 in the connecting plates 20. As shown by the top view in FIG. 2, 
these connecting plates 20 extend in the direction of conveyance of the 
conveyor chain over the entire width of the supports 10. The supports 10 
have a sealing element 40 on one front end, which seals against the front 
end of the connecting plate 20 of the adjacent support 10, so that the 
support plates 20, which are aligned in the direction of conveyance, have 
a closed, sealed top. The conduit rail 22, forming a suction conduit 23, 
is supported on this top of the connecting plates 20. The suction conduit 
23 extends over the entire transport path and is closed off at the ends. 
The conduit rail 22 is supported by the front ends of its side rail on the 
connecting plates 20 in such a way that the suction conduit 23 encloses 
the holes 21 of the connecting plates 20. The conduit rail 22 can be 
resilient in order to obtain a tight connection between the side legs of 
the conduit rail 22 and the connecting plates 20, which does not leak even 
when the conveyor chain is transporting. 
A connector 24 with the bore 25 branches off the suction conduit 23. A 
suction hose 26 with an inner receiver 27 is pushed onto the connector 24 
and leads to the central supply unit which, in the present case, generates 
suction air in a sufficient amount and of sufficient underpressure, so 
that all openings 11 of the supports 10 located under the suction conduit 
23 along the transport path can grasp objects by suction and hold them. 
When the support 10 leaves the transport path, i.e. the suction conduit, 
the object is released and can be removed or further transported. The 
conduit rail 22 can also be directly supported by the supports 10 and can 
enclose the holes 11 with the suction conduit 23. However, disposing the 
connecting plates 20 on the supports 10 has the advantage that they can be 
easily replaced if leaks occur after prolonged use. In this case, the 
connecting plates 20 are preferably releasably connected with the supports 
10 by means of screw connections. 
For transporting the supports 10, pairs of chain connection elements 28 and 
29 are fastened on the side of the supports 10 facing away from the 
transport side, namely on both sides of the connecting plates 20. The 
supports 10 are combined into the conveyor chain with the aid of chain 
members which bridge the joints between adjacent supports 10. The chain 
members permit the reversal of the conveyor chain with the aid of 
appropriately embodied chain gears. 
In the preferred embodiment shown in FIGS. 3 and 4, the holes 11 of the 
supports 10 are widened on the transport side, as shown by the enlargement 
12. By means of this the suction surface on the transport side is 
enlarged. The enlargement 12 of the hole 11 can be covered by an 
open-pored suction plate 35. When using a suction plate 35 made of 
open-pored plastic foam material, for example, the suction surface has a 
certain degree of inherent resilience, so that it can adapt itself to 
irregularities of the object grasped by suction. The suction plate 35 must 
be open-pored, so that many suction conduits are formed in the suction 
plate 35, which are all connected via the enlargement 12 with the hole 11 
of the support 10 charged with suction air. The hole 11 extends 
practically over the entire width of the support 10.