GB1593717A - Conveying system for shot or abrasive spray machines - Google Patents

Description

(54) CONVEYING SYSTEM FOR SHOT OR ABRASIVE SPRAY MACHINES (71) We, PROMECAM SISSON-LEHMANN, S.A., a Body Corporate organised under the Laws of France, of 63, Rue de Strasbourg, Saint Denis, Seine-Saint-Denis, France do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be described in and by the following statement: The present invention relates to a conveying system for use with shot or abrasive spray machines, designed notably for foundry castings.

As is known, castings coming from the mould have to be stripped of their sand matrix and for this purpose, they are sent to installations where they are subjected to jets of shot coming from turbines, When de-sanding of the parts of these castings which are exposed to the jets of shot has been completed, it is necessary to turn the castings over in order to remove the sand still adhering to the face on which they were resting during the first part of the shotting.

This shotting operation is completed by directing the jets of shot on to the parts of the casting which had not initially been exposed.

In order to do this, several methods of turning over are known. In a first form, use is made of vibrating plates at different heights: with this device there is the risk of packing, turning over the castings is uncertain and moreover it is extremely noisy.

In a second known embodiment, use is made of manipulators, e.g. turning bars, which grip the casting mechanically. These manipulators have to be set for each casting dimension, and the castings must therefore have constant dimensions and reach the manipulator in a predetermined position.

In addition to these limitations, it is found that the afore-said manipulators are subject to high risks of jamming.

A third known embodiment consists of using rotary drums, through which the castings to be stripped are passed. These devices also lack reliability, are noisy and moreover the rate of advance of the castings is irregular and depends on their size.

In most cases, these devices involve a manual operation, upstream of the conveyor, which is a further inconvenient constraint.

The aim of the invention is to overcome these drawbacks by making it possible to make a conveying system capable of reliably turning over the castings to be stripped, with no manual operation.

For this purpose, the conveying system with turning over for shot or abrasive spray machines covered by the invention is characterised in that it includes means of automatically turning over the castings for treatment in order to subject the faces of the castings on which the latter are resting at the start of treatment, to the direct action of the shot at the end of shotting or of the abrasives at the end of de-scaling.

The system according to the invention can conveniently be inserted into an automatic moulding or forging plant and the belts of endless chains can tip directly into said conveying system. Moreover, the latter can handle hot castings at temperatures of up to 500 or 6000C.

According to the invention we provide a conveying system for turning over castings in shot or abrasive spray machines, including two conveyors each consisting of an endless chain formed by an assembly of transverse strips or slats articulated rotatingly in relation to one another, these endless chains being capable of turning around two terminal driving spindles and the two belts formed by these chains being arranged one after the other with the upstream belt situated at a higher level than the downstream belt and extending over the end of the latter, wherein the strips of the upstream conveyor are fitted along their leading edges with angled lips projecting above the strips and extending transversely of the conveyor, said lips comprising bars inclined at a predetermined angle to the strips to provide upturned hooks which hold the castings at the start of their fall towards the downstream belt.

When the strip(s) on which a specific casting is resting arrives over the downstream belt and initate(s) a rotary movement towards the latter, the casting slides on the strip and is held during the first part of its fall by the angled lip in front of which it is placed. In these circumstances, it can be seen that if the height of the angled lip is suitable, it holds the casting at the beginning of its fall over a part of its trajectory which is just sufficient for the casting to have started a tilting movement, at the end of which it arrives, turned over, on the bottom belt.

This result is therefore obtained automatically, with no manual operation, and it is found that it is achieved with excellent reliability, irrespective of the dimensions of the castings to be stripped.

Other peculiarities and advantages of the invention will emerge from the description which will follow. The attached drawings, given as a non-limiting example, show a form of embodiment of the invention.

Figure 1 is a perspective view, partly exploded, of a form of embodiment of the conveying system according to the invention.

Figure 2 is an elevation view of the end of the conveying system in Figure 1.

Figure 3 is a part longitudinal elevation view of the conveyor belts which can be seen in Figures 1 and 2, showing the kine-matics of the fall of a casting.

Figure 4 is a part elevation view on an enlarged scale showing two consecutive strips and their angled lips.

Figure 5 is a vertical section view on an enlarged scale of the device for adjusting the height of the top conveyor belt.

Figure 6 is a part perspective view of the adjusting device in Figure 5.

The conveying system shown in Figures 1 to 3 is designed for shot or abrasive spray machines which can be used either for de-sanding foundry castings or in an ironworks for de-scaling forgings produced on an automatic machine.

The tunnel-type shotting machine is equipped with turbines which can spray jets of shot from top to bottom on to the castings covered with sand of which they have to be stripped. The shotting device is known in itself and has therefore not been shown.

This conveying system includes, according to the invention, means of automatically turning over foundry castings 1, 2, 3, 4, etc., which are to be stripped, in order to subject the faces of castings 1, 2, 3, 4, etc., on which these are resting at the start of the shotting or de-scaling operation to the direct action of the shot at the end of the shotting or to the action of the abrasive.

In the form of embodiment shown, the system covered by the invention comprises two conveyor belts 5, 6 each consisting of an articulated endless chain 7, 8 respectively.

Chains 7 and 8 can each rotate around two horizontal terminal spindles rotated by motors which are not shown, only the trailing spindles 9 and the leading spindle 11 respectively associated with chains 7 and 8 being visible in the figures. The ends of the driving spindles of chains 7 and 8 are engaged in longitudinal members 12 and 13 fixed to vertical uprights 14 and 15 which bear on parallel longitudinal beams 16, linked at their ends by cross-pieces 17.

The two belts 5 and 6 are arranged one after the other with the upstream belt 5 positioned at a higher level than downstream belt 6 the belt 5 extending over the corresponding upstream end of said downstream belt 6, as can be seen in Figure 3. The two belts formed by chains 7 and 8 each consist of an assembly of similar transversal strips or slats, 18 and 19 respectively, strips 19 forming chain 8 being distinctly longer than strips 16 in chain, 7 as can be seen in Figure 2. Bottom belt 6 is therefore wider than top belt 5.

According to an important feature, the invention provides for the slats or strips 18 of top belt 5 to be fitted with transversal angled lips 21 of predetermined height to hold castings 1,2,3,4, etc., at the start of their fall towards downstream belt 6.

In order to simplify the drawing the articulations between strips 18 and 19 have not been shown in Figure 3. Each strip 18 is fitted, along its leading edge facing towards downstream belt 6, with a bar 22 fixed to said leading edge e.g. by welding, and which in the upstream direction symbolised by arrow A(Figure 3) has an angled lip 21 on which the castings 1, 2, 3, 4, etc., for stripping hook. Angled lips 21 have a height h while bars 22 are slanted on strips 18 at an angle A.

By way of example, the following numerical values are possible: width d of each strip 18: about 100 mm; height h between about 6 and 8 mm; distance between two angled lips 21: 110 mm; width of a bar 22: 25 mm; angle A: preferably 25 degrees. This angle determines the point of unhooking at a distance less than height H, the latter being the distance which separates the spindle 9 rotating top belt 5 from strips 19 of bottom belt 6.

According to a further feature, upstream belt 6 is fitted with a device to adjust its height H above downstream belt 6, as a function of the height of castings 1, 2, 3,4 for stripping. This device consists of side pins 26 which go through two uprights 14 (Figures 5 and 6) through holes 23 formed in the uprights at different heights.

Pins 26 are thus engaged in plates 28 welded to longitudinal members 12.

To allow for the fact that the ends of longi tudinal members 12 adjoining uprights 14 go through an arc of a circle when their height is varied, holes 23 (three in number in the example described) are formed in an arc of a circle, as can be seen in Figure 1. In each upright 14 there are two additional holes 25 superimposed under holes 23 and these holes 25 can be used for possible adjustment of the height of bottom belt 6, in a similar way.

Each belt 5, 6 is equipped with a motor, not shown, making it possible to drive it at the same speed as the other belt or at a different speed. Bottom belt 6 comprises transversal slats 19 fitted with angled lips 27, in the same way as slats 18.

The technical effects and advantages of the conveying system according to the invention are as follows.

When the motors rotating spindles 9 and 11 are started up, articulated conveyor belts 7 and 8 turn at a speed which may, e.g., be from about 1 to 5 metres per minute. Beforehand, height H of top belt 5 over bottom belt 6 has been pre-set, as a function of the average dimensions of the castings to be de-sanded or descaled, by means of the device shown in Figures 5 and 6.

Castings 1, 2, 3,4 etc., termed "bunches" having varying configurations and dimensions, are tipped in any way on to the upstream belt 5 (e.g. from another feed belt). The kinematics of the fall of a casting 4 has been shown in Figure 3.

Casting 4 in question is astride an angled lip 21, resting on two consecutive strips 18. As the chain moves in the direction indicated by arrow F, casting 4, as it moves on upstream belt 5, undergoes the action ofjets of shot or abrasives which de-sand or de-scale the part thereof exposed to the jets in question. This phase of shotting or de-scaling is completed when casting 4 arrives substantially at spindle 9 around which the strips of chain 7 are turning. When the casting goes beyond the vertical position passing through spindle 9, it starts to slip downwards, at the end of which slip it is checked by the hooking angled lip 21 and assumes the position referenced 4a in Figure 3.

As rotation of pallets 18 continues (arrow R), the slant of casting 4a increases, with angled lip 21 still holding the casting. This phase of the trajectory is shown by casting position 4b. As rotation around spindle 9 continues, casting 4b goes beyond the horizontal plane passing through horizontal spindle 9, still held by angled lip 21.

At the end of this phase of its fall towards downstream belt 6, the casting is in position 4c, where it is at the limit of holding by angled lip 21.

Beyond this position, the casting hooks from angled lip 21 and falls freely towards belt 6, continuing the overturning movement which it had begun because it was held by angled lip 21 until it was in position 4c. The casting tips over itself as it falls (position 4d) and is received by strips 19 of downstream belt 6, in position 4e, turned over in relation to its initial position 4 on belt 5. Belt 6, rotated around horizontal spindle 11 in the clockwise direction indicated by arrow R', at a speed equal to or different from that of belt 5, removes overturned casting 4e (position 4f). The casting thus presents to the jets of shot or abrasives from the turbines positioned above downstream belt 6, the face on which it was resting during the shotting to which it was subjected on top belt 6.It can be seen that this turning over is done in a sure and therefore extremely reliable way, irrespective of the distribution of the castings on feed belt 5 and regardless of their dimensions.

However, as has already been indicated, height H of upstream belt 5 above downstream belt 6 must be determined beforehand. This setting is made as a function of the average dimensions of a batch of castings for stripping; height H can vary in a range preferably comprised between 1.1 and 1.5 times the largest dimension of the castings for treatment.

The flow of castings may vary very flexibly, because of the possibility of independently adjusting the forward speeds of the two articulated chains 7 and 8. Another advantage of the conveyor belt system according to the invention is that it makes it possible to turn over castings or forgings which vary widely, both in dimensions and geometry, without it being necessary to present them in a particular position or distribution, unlike previous systems.

Angled lips 27 on bottom belt 6 check the rolling of more or less round-shaped castings and limit the movement of said castings by stopping their slide after rebounding. Slats 19 so made, similarly to slats 18, are very strong and can stand up to the wear from the shot.

Moreover, no jamming of the castings for stripping can occur with the conveying system according to the invention, unlike some known devices such as turning bar systems.

The invention is not limited to the embodiment described and may comprise variants. The supporting frame of the conveyor belts may be more or less elaborate in shape, and two side jacks can be used to adjust height H to the required value, if this adjustment has to be made frequently. Moreover, slats 18 and 19 can come in varying shapes, with higher or lower flanges.

WHAT WE CLAIM IS: 1. A conveying system for turning over castings in shot or abrasive spray machines, including two conveyors each consisting of an endless chain formed by an assembly of transverse strips or slats articulated rota tingly in relation to one another, these endless chains being capable of turning around two terminal driving spindles and the two belts formed by these chains being arranged one after the other with the upstream belt situated at a higher level than the downstream belt and extending over the end of the latter, wherein the strips of the upstream conveyor are fitted along their leading edges with angled lips projecting above the strips and extend ing transversely of the conveyor, said lips comprising bars inclined at a predetermined angle to the strips to provide upturned hooks which hold the castings at the start of their fall towards the downstream belt.

2. A conveying system as claimed in claim 1, wherein the upstream belt is fitted with a device to adjust its height above the downstream belt, as a function of the largest dimension of the castings to be treated.

3. A conveying system as claimed in claim 1 or 2, wherein each belt is equipped with a motor making it possible to drive it at the same speed as the other belt or at a different speed.

4. A conveying system as claimed in claim 1, 2 or 3, wherein the slats of the downstream belt

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. When the motors rotating spindles 9 and 11 are started up, articulated conveyor belts 7 and 8 turn at a speed which may, e.g., be from about 1 to 5 metres per minute. Beforehand, height H of top belt 5 over bottom belt 6 has been pre-set, as a function of the average dimensions of the castings to be de-sanded or descaled, by means of the device shown in Figures 5 and 6. Castings 1, 2, 3,4 etc., termed "bunches" having varying configurations and dimensions, are tipped in any way on to the upstream belt 5 (e.g. from another feed belt). The kinematics of the fall of a casting 4 has been shown in Figure 3. Casting 4 in question is astride an angled lip 21, resting on two consecutive strips 18. As the chain moves in the direction indicated by arrow F, casting 4, as it moves on upstream belt 5, undergoes the action ofjets of shot or abrasives which de-sand or de-scale the part thereof exposed to the jets in question. This phase of shotting or de-scaling is completed when casting 4 arrives substantially at spindle 9 around which the strips of chain 7 are turning. When the casting goes beyond the vertical position passing through spindle 9, it starts to slip downwards, at the end of which slip it is checked by the hooking angled lip 21 and assumes the position referenced 4a in Figure 3. As rotation of pallets 18 continues (arrow R), the slant of casting 4a increases, with angled lip 21 still holding the casting. This phase of the trajectory is shown by casting position 4b. As rotation around spindle 9 continues, casting 4b goes beyond the horizontal plane passing through horizontal spindle 9, still held by angled lip 21. At the end of this phase of its fall towards downstream belt 6, the casting is in position 4c, where it is at the limit of holding by angled lip 21. Beyond this position, the casting hooks from angled lip 21 and falls freely towards belt 6, continuing the overturning movement which it had begun because it was held by angled lip 21 until it was in position 4c. The casting tips over itself as it falls (position 4d) and is received by strips 19 of downstream belt 6, in position 4e, turned over in relation to its initial position 4 on belt 5. Belt 6, rotated around horizontal spindle 11 in the clockwise direction indicated by arrow R', at a speed equal to or different from that of belt 5, removes overturned casting 4e (position 4f). The casting thus presents to the jets of shot or abrasives from the turbines positioned above downstream belt 6, the face on which it was resting during the shotting to which it was subjected on top belt 6.It can be seen that this turning over is done in a sure and therefore extremely reliable way, irrespective of the distribution of the castings on feed belt 5 and regardless of their dimensions. However, as has already been indicated, height H of upstream belt 5 above downstream belt 6 must be determined beforehand. This setting is made as a function of the average dimensions of a batch of castings for stripping; height H can vary in a range preferably comprised between 1.1 and 1.5 times the largest dimension of the castings for treatment. The flow of castings may vary very flexibly, because of the possibility of independently adjusting the forward speeds of the two articulated chains 7 and 8. Another advantage of the conveyor belt system according to the invention is that it makes it possible to turn over castings or forgings which vary widely, both in dimensions and geometry, without it being necessary to present them in a particular position or distribution, unlike previous systems. Angled lips 27 on bottom belt 6 check the rolling of more or less round-shaped castings and limit the movement of said castings by stopping their slide after rebounding. Slats 19 so made, similarly to slats 18, are very strong and can stand up to the wear from the shot. Moreover, no jamming of the castings for stripping can occur with the conveying system according to the invention, unlike some known devices such as turning bar systems. The invention is not limited to the embodiment described and may comprise variants. The supporting frame of the conveyor belts may be more or less elaborate in shape, and two side jacks can be used to adjust height H to the required value, if this adjustment has to be made frequently. Moreover, slats 18 and 19 can come in varying shapes, with higher or lower flanges. WHAT WE CLAIM IS:

1. A conveying system for turning over castings in shot or abrasive spray machines, including two conveyors each consisting of an endless chain formed by an assembly of transverse strips or slats articulated rota tingly in relation to one another, these endless chains being capable of turning around two terminal driving spindles and the two belts formed by these chains being arranged one after the other with the upstream belt situated at a higher level than the downstream belt and extending over the end of the latter, wherein the strips of the upstream conveyor are fitted along their leading edges with angled lips projecting above the strips and extend ing transversely of the conveyor, said lips comprising bars inclined at a predetermined angle to the strips to provide upturned hooks which hold the castings at the start of their fall towards the downstream belt.

2. A conveying system as claimed in claim 1, wherein the upstream belt is fitted with a device to adjust its height above the downstream belt, as a function of the largest dimension of the castings to be treated.

3. A conveying system as claimed in claim 1 or 2, wherein each belt is equipped with a motor making it possible to drive it at the same speed as the other belt or at a different speed.

4. A conveying system as claimed in claim 1, 2 or 3, wherein the slats of the downstream belt

are also fitted with transversal angled lips similar to those on the upstream belt.

5. A conveying system substantially as described herein with reference to the accompanying drawings.