EP3736046A1 - Retraction prevention - Google Patents

Abstract

The invention comprises a draw-in protection for a rolling mill with a housing and several parallel rotating rollers, a product intake being formed by two of the rollers which rotate about axes of rotation arranged parallel to one another and are arranged at an adjustable roller distance from one another. The intake protection comprises a profile which is arranged parallel to the rollers forming the product intake and extends over the length of the product intake. In a feed direction of the rotating rollers, the profile is upstream of the rollers forming the product feed. At least one vertical through opening is formed in the profile. A gap is formed between the profile and the rollers. The draw-in protection also comprises a holder for fastening the draw-in protection to the housing of the rolling mill

Description

The present invention relates to a draw-in protection for rolling mills with a plurality of rotating rolls, in particular three-roll mills.

Three-roll mills are suitable for a wide range of applications. The systems are designed for processing medium to high viscosity masses. Three-roll mills can be used for the production of printing inks of all kinds, artist's paints, industrial and building paints, toners, but also coating compounds, greases and products for the electronics and cosmetics industries. In the operation of rolling mills, a substance or mixture of substances is fed and dispersed between two rotating rollers, between which a gap is formed. At the roller on the product exit side, the finished product is removed from the roller, for example by means of a scraper, and carried away.

As a rule, a rolling mill also includes various safety mechanisms to ensure occupational safety during operation or during cleaning. One or more emergency stop buttons can be provided on the housing in order to be able to stop the machine quickly if necessary. This can e.g. be implemented by means of an AC converter with a dynamic braking system. Furthermore, a cover can be provided which completely closes the machine and thus prevents personnel from being injured on the machine or objects from getting into the product intake.

From the prior art, for example, safety covers are known which are attached over a feed opening of the rollers. With the safety cover closed, however, it is difficult or impossible to feed or distribute product and to detect dry running. The open rollers are often used to feed a product or to be able to distribute it over the entire width of the roller. However, there is a risk of objects or body parts getting between the rollers. The object of the present invention is therefore to ensure increased work safety in order to protect personnel and equipment.

This object is achieved by a draw-in protection according to independent claim 1. The dependent claims describe preferred embodiments.

In particular, the invention comprises a draw-in protection for a rolling mill with a housing and several parallel rotating rollers, a product feed being formed by two of the rollers that rotate about axes of rotation arranged parallel to one another and are arranged at an adjustable roller distance from one another. The intake protection comprises a profile which is arranged parallel to the rollers forming the product intake and which extends over the length of the product intake. In a feed direction of the rotating rollers, the profile is upstream of the rollers forming the product feed. At least one vertical through opening is formed in the profile. A gap is formed between the profile and the rollers. The draw-in protection also comprises a holder for fastening the draw-in protection to the housing of the rolling mill.

The draw-in protection can furthermore have two bars arranged parallel to the rollers forming the product draw-in, the bars being upstream of the rolls forming the product draw-in in a draw-in direction of the rotating rollers. A gap can be formed between the rods. Furthermore, a distance can be formed between the rods and the rollers.

The rods preferably have a rectangular cross section. The distance between the bars and the rollers can be adjustable. The draw-in protection further comprises a removable spatula for cleaning the rollers and / or bars and / or for distributing a product on the rollers. The spatula is preferably designed in such a way that it can be arranged in the gap between the rods.

The draw-in protection is preferably made of a rustproof metal. Furthermore, the draw-in protection can be coated or polished in order to prevent a product from sticking to the draw-in protection. The rods can be connected to the bracket via a linkage. An angle between the linkage and the bracket is preferably less than or equal to 90 °. The draw-in protection can furthermore comprise a device in order to stop the rolling mill in the event of incorrect positioning or if the draw-in protection is missing. The device for stopping the rolling mill can be designed as a magnetic switch.

The invention further comprises a rolling mill with a draw-in protection according to the present invention. The rolling mill can further comprise two buttons which, when actuated at the same time, start an idle mode with reduced speed of the rolling mill. The buttons are preferably spaced from one another in such a way that they cannot be operated with one hand at the same time.

The invention further comprises a method for retrofitting a rolling mill with the draw-in protection according to the invention. A rolling mill is provided for this purpose, the draw-in protection is attached to it by means of the holder and the distance between the rolls and bars is adjusted by means of the height adjustment.

• Fig. 1: Eine Querschnittansicht eines Walzwerks mit Einzugschutz gemäß einer Ausführungsform der Erfindung
• Fig. 2: Eine Detailansicht des Einzugschutzes aus Fig. 1
• Fig. 3: Eine perspektivische Ansicht des Einzugschutzes
• Fig. 4: Eine seitliche Ansicht eines erfindungsgemäßen Walzwerks mit Einzugschutz
• Fig. 5: Eine frontale Ansicht eines erfindungsgemäßen Walzwerks mit Einzugschutz.

The present invention is explained in more detail with reference to the drawings. In the drawings, the same reference symbols are used for the same or similar elements. Show it:

• Fig. 1 : A cross-sectional view of a rolling mill with draw-in protection according to an embodiment of the invention
• Fig. 2 : A detailed view of the pull-in protection Fig. 1
• Fig. 3 : A perspective view of the anti-trap
• Fig. 4 : A side view of a rolling mill according to the invention with draw-in protection
• Fig. 5 : A front view of a rolling mill according to the invention with draw-in protection.

Figure 1 Figure 11 shows a partial side view of a rolling mill according to an embodiment of the invention. For the sake of clarity, only two rollers 7 are shown, but more than two rollers can be provided depending on the application. The rolling mill comprises a housing 9 and the rollers 7, which each rotate about an axis of rotation 71 and whose spacing from one another can be adjustable. Furthermore, a feed opening or a product intake 8 is provided which is formed between two rollers 7 and through which the starting material or the mixture of substances is fed to the rollers 7 and dispersed between them. For this purpose, adjacent rollers 7 are operated in opposite directions and are usually filled from above. The product intake 8 can also comprise further means for guiding the product between the rollers 7, for example a funnel-shaped arrangement.

When dispersing fats or highly viscous substances, for example, they can settle on the side walls of the rolling mill, which means that the personnel must intervene. Therefore, a draw-in protection is provided according to the invention, which maximum safety when working on the open machine is guaranteed. Thus, during operation, smoothing can be done without great effort, ie product can be distributed or refilled on the rollers 7, and dry running can be recognized without endangering the personnel.

The intake protection comprises a profile which is arranged parallel to the rollers 7 forming the product intake 8 and extends over the length of the product intake 8. The profile is upstream of the rollers 7 forming the product intake 8 in a feed direction of the rotating rollers 7. At least one vertical through opening is formed in the profile. A distance d is formed between the profile and the rollers 7. The draw-in protection further comprises a holder 4 for fastening the draw-in protection to the housing 9 of the rolling mill.

A plurality of through openings spaced from one another can also be provided in the profile. These can enable a product flow or a product circulation as below with reference to FIG Figure 2 is described. The through openings can be designed as slots or holes, for example, but other shapes can also be expedient. The profile preferably extends over the entire length of the product intake 8, but it can also be made shorter.

According to a preferred embodiment that is described in Figure 1 As shown by way of example, the draw-in protection comprises two rods 3, which are arranged parallel to the rollers 7 forming the product feed-in 8 and are positioned in front of the rollers 7 in the feed-in direction. In other words, the through opening extends over the entire length of the profile of the draft guard. In the following and in the drawings, reference is made to this embodiment. A gap s is formed between the rods 3. The gap s is preferably narrow enough to prevent fingers or objects from getting between the rollers 7 and wide enough to enable product to be fed.

The profile or rods 3 can be attached directly to the housing 9 on the side walls of the product intake 8 or inserted into the product intake 8 from above by means of a rod 1 and a holder 4 and secured. This creates a distance d between the profile or the bars 3 and the respective roller 7, as in FIG Figure 2 shown. This distance d can preferably be set by means of a height adjustment 6. The height adjustment 6 can, for example, by means of rotary handles 5, which cover the entire pull-in protection move up or down when turning or be adjusted by spacer discs. This also makes it possible to feed product to the rollers 7 through the distance d. The distance d is between 3 and 10 mm, preferably 4-6 mm, particularly preferably 5 mm.

A level probe can be provided above the gap between the rollers 7 or the product intake 8 in order to monitor the product filling. The level probe can be designed as an ultrasonic probe, for example. If the probe is arranged vertically above the product intake 8, it can be expedient for the linkage 1 to be arranged at an angular offset to the holder 4 so as not to interfere with the level probe. The angle between linkage 1 and bracket 4 or between linkage 1 and a horizontal plane through bracket 4 is thus less than 90 °.

Figure 2 shows a detailed view of section D of Figure 1. Figure 2 again shows the embodiment with two bars 3 arranged in parallel, between which a gap s is formed. However, the explanations apply analogously to a pull-in protection with only one profile. During operation, the product is fed in by rotating the rollers 7 through the distance d. It can then exit upwards through the passage openings of the draw-in protection or the gap s and slide over the profile or the rods 3 in the direction of the distance d in order to be fed to the rollers 7 again. In other words, the upper side of the profile or rods 3 facing away from the product intake is preferably convex or tapering upwards so that product that has escaped through the gap s or the passage openings can slide down and be fed to the rollers 7. In particular, it is advantageous that no horizontal surface is formed on the upper side so that no product adheres or remains lying. This results in the product circulating around the draw-in protection. It has been shown that rectangular profiles of the bars 3 achieve the best results with regard to the adhesion of the product, that is to say that significantly less product adheres to rectangular profiles in comparison to smooth profiles. In particular, it is advantageous that each point of the rectangular profile points upwards in the direction of the product intake 8 and one point in the opposite direction. This results in a roof-shaped structure on the top. Furthermore, when the product circulates, there may be high pressure from below on the draw-in protection, which can lead to deformation of the draw-in protection. Therefore, the relief opening is preferably formed over the entire length of the draw-in protection. In other words, the profile is designed in two or more parts. Also Round profiles showed good properties and little adhesion, but are more difficult to clean and therefore less preferred. The rods 3 are preferably made of stainless steel. This can be glass blasted and polished to further reduce the adhesion of the product to it.

Furthermore, if the profile is designed in two parts with a gap s, the draw-in protection can comprise a spatula 2 which is removably arranged in the gap s. The shape of the spatula 2 is preferably adapted to the gap s and the shape of the rods 3. As a result, filling can be carried out in regular operation or in cleaning operation in order to distribute the product evenly in the product intake 8 or to remove it from the rollers 7 and the rods 3 in order to clean the intake protection.

Figure 2 also shows the removable spatula 2 arranged in the gap s for cleaning the rods 3 and / or rollers 7.

Figure 3 shows a view of the dismantled draw-in protection according to an embodiment with a two-part profile. A safety mechanism 41 can be provided on one side, which ensures that the rolling mill is only operated when the draw-in protection is installed. The safety mechanism 41 can, for example, have a corresponding counterpart on the housing 9 and be designed as a magnetic switch. Thus, the rollers 7 can only be rotated when the anti-feed device is installed and are stopped in operation if they are removed.

Figure 4 is an oblique view of the rolling mill with built-in anti-trap as described above.

Figure 5 shows a front view of a rolling mill with built-in draw-in protection. In this illustration, the profile or the bars 3 extend over the entire length of the product intake 8. The lateral boundary walls of the product intake 8 are also referred to as a wedge, since they delimit the space between the rollers 7 in a wedge shape. The linkage 1 is preferably designed as two connecting rods between the holder 4 and the profile or rods 3 in order to ensure stability in the operation of the rolling mill. In order to ensure that the product is troweled over the entire width of the product intake 8, the distances b ₁ , b ₂ and b ₃ between the product intake 8 and the linkage 1 or between Linkage 1 and linkage 1 or between linkage 1 and product intake 8 are preferably of a similar size. The distances b ₁ , b ₂ and b _{3 are} measured depending on the machine size. In particular, however, the distances b ₁ and b _{3 are designed in} such a way that the operator can easily fill in the sides.

The rolling mill can also have an idle mode, in which the rollers 7 are operated at a reduced speed in order to remove product residues and to empty the machine. The speed can be, for example, 300-400 rpm. Furthermore, the machine can have a holder in order to hang the draw-in protection above the product draw-in 8. The pull-in protection is preferably positioned higher up after it has been attached than in operation, so that the staff can easily reach the pull-in protection. In this way, the operating personnel can remove product residues from the draw-in protection or apply a spatula and clean it. The product residues that have fallen down and any product remaining on the rollers 7 can then be removed from the machine using the empty travel mode. To activate the idle mode, two buttons (not shown) can be provided on the front of the rolling mill on the housing, which must be operated simultaneously. The buttons are preferably so spaced from one another that they cannot be operated with one hand. This can also prevent the personnel from reaching into the rotating rollers 7.

The invention further comprises a method for retrofitting a rolling mill with a draw-in protection. The pull-in protection is used in the rolling mill for this purpose. The draw-in protection is preferably used in the product infeed 8, i.e. above the rollers 7, in particular the rollers that form the product intake. The distance d between rollers 7 and bars 3 can be adjusted by means of the height adjustment 6.

According to the present invention, safety in operation can thus be improved and operation can be simplified. In particular, it is possible to work on the open machine without there being a risk of injury to personnel or the risk of damage to the machine. This makes it easier to refill product or, in the case of deposits on the side walls, fill it with a spatula in order to distribute the product evenly on the rollers and a dry run can be recognized more easily.

List of reference symbols

1

Linkage

2

spatula

3

Bars

4th

bracket

41

Safety mechanism

5

Handle

6th

Height adjustment

7th

roller

71

Axis of rotation

8th

Product collection

9

casing

b ₁ -b ₃

Distance of the linkage

d

distance

s

gap

Claims (12)

Infeed protection for a rolling mill with a housing (9) and several parallel rotating rollers (7), whereby two of the rollers (7), which rotate about axes of rotation (71) arranged parallel to one another and are arranged at an adjustable roller distance from one another, enable a product intake ( 8), whereby the pull-in protection has: a profile which is arranged parallel to the rollers (7) forming the product intake (8) and extends over the length of the product intake (8), wherein the profile in a direction of intake of the rotating rollers (7) corresponds to the rollers (8) forming the product intake (8) 7) is upstream, wherein at least one vertical through opening is formed in the profile, and a spacing (d) being formed between the profile and the rollers (7), and a holder (4) for attaching the draw-in protection to the housing (9) of the rolling mill. Entry protection for a rolling mill according to Claim 1, the profile having two bars (3) arranged parallel to the rollers (7) forming the product intake (8), with a gap (s) being formed between the bars (3), which forms the through opening forms. Draw-in protection for a rolling mill according to claim 2, wherein the bars (3) have a rectangular cross-section. Draw-in protection for a rolling mill according to one of Claims 1 to 3, the distance (d) of the profile to the rollers (7) being adjustable. Draw-in protection for a rolling mill according to one of Claims 1 to 4, the draw-in protection further comprising a removable spatula (2) for cleaning the rollers (7) and / or the profile and / or for distributing a product on the rollers (7), and
wherein the spatula is designed such that it can be arranged in the gap (s) between the rods (3). Draw-in protection for a rolling mill according to one of the preceding claims, wherein the draw-in protection is formed from a stainless metal, and
wherein the draw-in protection is preferably coated or polished in order to prevent a product from sticking to the draw-in protection. Draw-in protection for a rolling mill according to one of the preceding claims, wherein the profile is connected to the holder (4) via a rod (1), and
wherein an angle less than or equal to 90 ° is formed between the rod (1) and the bracket (4). Draw-in protection for a rolling mill according to one of the preceding claims, wherein the draw-in protection further comprises a device (41) in order to stop the rolling mill in the event of incorrect positioning or absence of the draw-in protection. Pull-in protection for a rolling mill according to claim 8, wherein the device (41) for stopping the rolling mill is designed as a magnetic switch. Rolling mill with a draw-in protection according to one of Claims 1 to 9. The rolling mill according to claim 10, wherein the rolling mill comprises two operating elements which are set up to start an idle mode with reduced speed of the rolling mill when actuated at the same time, the buttons being spaced from one another in such a way that they cannot be operated simultaneously with one hand. Method for retrofitting a rolling mill with the draw-in protection according to one of Claims 1 to 9, the method comprising: Provision of a rolling mill, Insertion of the feed protection over the product feed (8), Adjust the distance (d) using the height adjustment (6).

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