EP0669859B1 - Bar introduction device - Google Patents

Abstract

The invention is concerned with a mechanical device suitable for introduction and positioning of metal bars or rods or metal profiles of any section and length used preferably on machines for the production of electrowelded normal or special meshs, shaped according to drawing, through particular flanked double chained means of transport (4) having the purpose to feed and position a plurality of bars (1) at the same time on the collecting surface (9). Said couples of chains (4), parallel and vertical, at closed run, are moved by toothed wheels (6) of large curving ray and by others of smaller ray (5.1 - 5.2). Each chain carries on the outside a plurality of teeth or slabs with lateral semicircle gap, all directed in the same sense: therefore in a single couple of chains, one chain will have slabs (7) in one direction while the other flanked chain has the opposite (8) in order to form a plurality of housings suitable to receive, transport and place bars (1).

Description

The present invention concerns an automatic introduction device for bars or metal straight rods of any section and length according to the preamble of claim 1, preferentially on machines for the production of an electrowelded mesh of normal or special, shaped according to drawing, through particular double chain transport means having the goal to feed and position a plurality of bars in synchrony.

At technical's state of things, we know different positioning systems for bars or metal rods to provide distribution on level to realize (to make) electrowelded meshes. A system is known which requires workman intervention to set and position rods by means of an automatic feeder which carries one bar at the time with well defined geometrical characteristics.

Such a system is very slow, therefore weighs considerably on production and on product's unit price.

A device for arranging and storing cylindrical objects one by one comprising a closed run transporting chain having slabs receiving and releasing said cylindrical objects at points of small curve radius is known from FR-A-992 887, on which the preamble of claim 1 is based. However, simultaneous unloading of a plurality of objects is not possible with such a device according to the prior art.

Considered the inconvenients of well-known machines it was thought to realize an automatic introduction device which could reduce production time and automate positioning operation of section bars of any dimensional feature on the working level. As a matter of fact, for special electrowelded mesh construction it is necessary to place bars of different lengths and sections with various arrangements on the level in parallel, equidistant or not.

Accordingly, it is an object of the present invention to provide a system permitting, under command, simultaneous placing in the right position of a plurality of bars variously distributed and combined to each other without the use of magnetism.

This object is achieved by an automatic introduction device for bars or metal straight rods according to claim 1. Preferred embodiments of the present invention are set out in the dependent claims.

The device according to the invention is supplied by a feeder which supplies side ways, under command, one bar at the time of determined programmed dimensions, with a single edge reference even for bars having different lengths in order to facilitate welding operations, o any other, on the end side. Following is a set of particular transport chains, parallel and preferably disposed at different distances and orthogonal to the longitudinal axis or bars which have the task of taking the bars, carry them and place them in established positions. Each single chain is effectively composed by a flanked couple of chains, independently driven and running in a closed turn on toothed wheels of different diameters, each one carrying a plurality of slabs shaped towards the outside, forming a tooth with a semicircular lateral notch. Both flanked chains have all slabs placed in one direction: for one chain the slabs have one sense while for the other chain they have the opposite. Therefore, with the flanked chains moved in synchrony, the outer slabs will form a plurality of transversal housings, closed to the moving direction of themselves. The housing formed by two slabs has the particularity to open itself towards the outside whenever the chain links are been turned on the toothed wheel of smaller diameter, while the opening is very little on toothed wheels of larger diameter. Therefore, the housing formed by both flanked shaped slabs opens on the smaller radius curves and closes on the straight-line sections of the chain run even on the overturned chain run.

Therefore, the housings formed by the chains are suitable to keep one or more transversal bars which are introduced at points where the housing itself opens, whereby afterwards the housing closes and carries them avoiding any danger of release even on overturned straight-line sections. Obviously, in this way loading and unloading of bars is made separately, or rather in points where chains turn around a toothed wheel of small diameter. But the purpose of this invention is to realize simultaneous unloading of a plurality of bars on the suitable comb shaped collectors. This is possible only if between both chains there is the possibility of a relative light sliding of the shaped slabs.

This has been solved with the following technical expedient; each chain, forming the couple is moved separately by its proper motor axis. Both shafts can be moved by synchronized motors or by one motor with Cardan joint connection between one another. Relative movement of a flanked chain with respect to the other, to open the housing even on straight-line sections, is made through a light rotation of one axis with respect to the other one (for example this can be achieved by light feeding of a chain or rather small rotation angle of a motor "step by step" or of a "hanging" moved by an hydraulic fluid or pneumatic system, or any other technical solution well-known, etc.).

Such contrivance permits to realize a transporting chain for bars from an upper position, catching bars in the major curving point of the run (opening of single slabs), to a lower level with simultaneous placing of a plurality of bars on the overturned straight-line section, with fall for gravity on the collecting comb, upon command moving the flanked chain slabs relatively in the opening sense of the housing, whereby, after reseting such movement, the device is ready for a new cycle.

Through programmable command techniques this invention can receive, transport and place on a comb or collecting level, bars of any dimension in length and diameter at well defined distances between one another.

Flanked transport chains can be of any length and the outward projecting half-housing slabs can interest their perimeter fully or just in part.

The bar introduction device is capable to operate continuously independently from devices or machines at the end side of the plant: indeed it can load the bars and set them in position without interference with the comb level underneath and it can place the bars, upon command, at the same time only when this level is free.

The invention is exposed in details with the help of drawings showing preferred embodiments thereof.

Fig.1 is a side view of bar introduction unit, including distributor, special transporting chain and the bar collecting comb underneath.

Fig.2 is a partial side view of the opening procedure of the housing and bar transportation close to the maximum curving of chain (toothed wheel of small diameter).

Fig.3 is a side view of feeding compared to Fig.1 of flanked double chain.

Fig.4 is a partial side view if chain behaviour with housing slabs for bar keeping close to toothed wheels of large diameter without opening of the grip.

Fig.5 is a side view of the unit with the chain located in an overturned position close to the collecting comb.

Fig.6 is a partial side view, the enlarged zone of chain in its overturned position with slabs containing the bars.

Fig.7 is a side view the unit with overturned chain and slabs in comparative movement in the opening phase.

Fig.8 is a partial side view, enlarged overturned chain pointing out the slabs opening phase.

Fig.9 is a transversal section view of a chain couple with flanked outer slabs and their driving system by means of two motors.

Fig.10 is a front view of the bar transfering unit with seven couples of flanked chains placed in parallel at various distances.

Fig.11 is a plan view of the unit of Fig.10 pointing out a possible bar distribution of different lengths and different placings, with lined-up edge, ready to be positioned for the following welding phase and electrowelded mesh forming.

According to a preferred embodiment of the invention the automatic bar introduction device and positioning of the same to realise electrowelded mesh includes a frame metal structure composed by a collecting level or comb (9) and over this, vertically, a sequence of seven parallel flanked transporting chains (4) settled in different distances suitable to transport metal straight bars or rods (1) of different lengths on said comb level (9) underneath, orthogonally to bar container (2) placed sideways with a distribution device (3) placed near to the maximum curving point of the chain, in upper position, that is close to the toothed wheels (5.1 - 5.2) of smaller radius.

The flanked couple chains (4) butt two flanked independent toothed wheels, of smaller diameter (5.1 - 5.2), while at the other end engage with two wheels of larger diameter (6). Each chain (4) has on its outer side a plurality of shaped slabs with a vertical semicircular gap. One chain has all its slabs directed in one sense (7) while the other on the opposite sense (8) even if moving in the same direction. Both chains flanked are synchronized and suitably positioned, whereby the semicircular slabs form generally, two by two, a housing for bar keeping in the orthogonal sense which is also suitable for an overturned run section. Both flanked chains (4) are moved by two shafts and by means of two motors separately.

As a matter of fact, a shaft (10) is moved by a motor (11) and it is fixed to the wheel (5.1) moving chain (4) with the slabs (7) and the toothed flanked wheel (5.2) is idle. The other chain with the slabs (8) is moved by a second shaft (12) with motor (13), and also in this case the flanked wheel (5.2) is idle. Therefore relative sliding between both chains and slabs (7) and (8) can be realized, whereby simultaneous placing of the bars on the collecting comb (9) is carried out, due to gravity. As a matter of fact, if one of both motors moves, upon command, lightly out of synchrony or by using another system suitable to the purpose (ex. axial moving of a "hanging"), the housing formed by the slabs (7) and (8) opens.

Both flanked chains (4) with slabs (7) and (8) are partially distributed on perimeter, and when the slabs reach the maximum curving point close to the distributor (3) they open and receive the bar, then, on the straight-line section and at the large curving radius they close up keeping the bar even on the overturned run (due to the synchronized movement of both chains (4)). Once the placing point is reached, by relative movement of slabs (7) and (8) in the opening direction of housing, all their content falls at once, due to gravity, on the comb (9). Afterwards synchronity is reset and the transport chains are ready for a new cycle. Bars (1) settled on combs beneath (9) can have different section and length and have one edge lined-up close to the catching device before a welding device (14). Single receipt of bars on behalf of slabs (7) and (8) of chains (4), close to sideway distributor (3), is made through project programmed command and therefore distribution and consequent placing of the bars may also not be equidistant.

Claims (10)

1. Automatic introduction device for bars or metal straight rods (1) of any section and length for progressive programmed placing thereof on a positioning level, the device comprising a plurality of flanked coupled transporting chains (4), all of said couples of chains being located on vertical planes parallel to each other and each single transporting chain carrying a set of outer shaped slabs (7-8) having a semicircular gap, each gap being able to receive one of said bars, each of said plurality of flanked coupled transporting chains (4) running in a closed run on toothed wheels (5.1, 5.2, 6) of different diameters, said closed run having either straight-line sections and curved sections with differing curving radii, said plurality of flanked coupled transporting chains (4) receiving said bars (1) orthogonally from a bar distribution device (3) placed near a section having a curving radius smaller than the other and to transport and position the said bars (1) orthogonally on said positioning level (9) underneath, said introduction device being characterized in that:

   all slabs (7-8) of a first set of slabs of a chain of each couple of transporting chains are oriented according to the sense of feeding of their proper chain (4) while the remaining set thereof are opposite with respect thereto, each pair of corresponding slabs (7-8) of said two sets thereby forming a closed housing for the transport of bars (1) when running on said straight line sections and forming an open housing adapted to receive said bars (1) when running over said sections having said smaller curving radius, each of said transporting chains (4) of a couple being moved separately by its proper motor axis (10, 12), such that relative movement of the flanked chains (4) leading to relative light sliding of said slabs (7-8) can be carried out, and further characterized in that said device being controllable such as to transport the bars (1) received from said distribution device (3) along a portion of said closed run towards an overturned straight line section thereof being parallel to said positioning level (9) underneath where a relative movement is carried out between both flanked chains (4) forming said couple thereby achieving simultaneous unloading by gravity of a plurality of bars (1) on said positioning level underneath.
2. Bar introduction device according to claim 1, characterized in that said flanked chain couples (4) carrying the slabs (7-8) are moved by means of toothed wheels fixed (5.1) and held by idle toothed wheels (5.2) and in that said relative movement between both chains can be achieved by one of the following procedures: a) by simultaneous intervention on the two motors driving the single chains (4), whereby one continues light feeding while the other stops, or, one runs more quickly than the other, or also one stops and the other goes lightly backwards; b) or by synchronizing both motors (11-13) to each other, with one of them arranged radially movable by means of another system to put them out of phase for a short time; c) or by the use of one single motor to drive both axis with a Cardan joint and device for achieving a brief disengagement and engagement of the transmission.
3. Bar introduction device according to one or more of the previous claims, characterized in that said set of slabs (7-8) carried by the flanked chains (4) can cover the whole perimeter of said chains or could only be partial.
4. Bar introduction device according to one or more of the previous claims characterized in that it provides the use of at least two or more transporting chain couples (4).
5. Bar introduction device according to one or more of the previous claims characterized in that said couples of transporting chains (4) are disposed at different distances from each other such as to allow the orthogonal transport of bars of different lengths.
6. Bar introduction device according to one or more of the previous claims characterized in that said positioning level is a collecting comb (9).
7. Bar introduction device according to one or more of the previous claims characterized in that distribution, introduction and consequent bar placing, of any section and length can be continuous or alternating according to the step of the slabs carried by chains (4).
8. Bar introduction device according to one or more of the previous claims characterized in that the bar introduction is made by one by one or more at a time.
9. Bar introduction device according to one or more of the previous claims characterized in that it is programmed suitably to operate independently from devices or machines at the end side thereof.
10. Bar introduction device according to one or more of the previous claims characterized in that it is programmed suitably to distribute and consequently to place said bars (1) in a non-equidistant manner on said positioning level (9).

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