GB2342458A - In-line weighing on a roller table - Google Patents

Abstract

Apparatus for weighing semi-finished metal products, comprising a roller table 5 or 6 having a plurality of transport rolls 2 and load cell means on which the roller table is mounted. The load cell means comprise a plurality of load cells each supporting a respective transport roll bearing. The bearing housings are mounted on the ends of pivoting arms which are fixed via anti friction bearings and corresponding shafts to a simple "shallow" frame mounted to a fixed support. The pivot points of the pivot arms are upstream of the rollers, and the centre of the pivot point is essentially in the same horizontal plane as the roller centre.

Description

In-Line Weighing This invention relates to the arrangement of equipment required to weigh a product as it progresses along its production route, and more specificall ! the weighing of steel cast or rolled product whose size is such llial il is ready for us final hot rolling procedure. The cast or rolled product at this semi-finished stage is known as a"semi"product.

The weighing of"semi"product, possibly in the foiin of slab. bloom ou billet, is required by steelmakers to determine the relative yield of casting machines and the subsequent rolling mills; it is also used to confire the weiglit of the semi if they are sold in this state.

In the past the development of weighing devices lias progressed from a weighing system which lifts the static semi from the transport roller table which is essentially located above the roller table pass line to a lifting system which is located below the roller table pass line. The lifting of the semi has been superseded by a static weigh table requiring no moving parts but has heavy frames that support the roller table together between the measuring transduce ! s -loadcells-betweentheheavyframesandtheconcretecivilfoundations below. The load cells thus weigh the heavy frames, rolls and the semi itselt : The depth of the frame also complicates the construction of the civil engineering aspects of the system as well as making the addition of weighing to existing production facilities relatively more expensive.

The object of the present invention is to further improve the weighing of semis by not having a lifting device and simplifying the civil engineering requirements of existing known systems.

According to the present invention there is provided a system for the weighing of semi-finished metal products comprising a roller table comprised of a plurality of transport rolls supported on support bearings arranged in corresponding bearing housings, characterised in that each transport roll cowesponding to a section of the roller table is supported by shear beam load cells located vertically under the roller support bearings or bearing housings. and in which the bearing housings are formed on the ends of pivoting arms.

The pivoting arms are preferably fixed via an anti friction bearing/s and a corresponding shaft to a simple"shallow"frame mounted to a fixed support The pivot point of the pivot arm is preferably upstream of the roller but can be on the downstream side. This will minimise the effect of any residual internal forces arising from the rotational drive applied to the rolls.

The centre of the pivot point is preferably essentially in the same horizontal plane as the roller centre. The closer a line between the fixed pivot point centre and the acting roll centre line is parallel to the pass line of the object to be weighed, then the more accurate the measurement will be. This arises from minimising or eliminating any non-vertical components of load arising from the geometry of the system. The actual relationship of the line joining the fixed pivot point to the roll centre will be governed by the accuracy required of the weighing system.

Any significant friction occurring at the fixed pivot point will have the effect of reducing the load seen by the load cells. It is therefore preferable to include bearings into the fixed pivot point ; that will reduce this effect to an insignificant amount.

The number of rolls is determined by the amount of rolls in the roller table required to support the maximum length/weight of the seini finished material.

The signals fi-om all the load cells are added together and the tare weight of the rolls deducted to determine the weight of the semi finished material itself.

The size/capacity of the load cell is determined according to the maximum weight of the semi and the worst possible loading case i. e. multiple roller support, shape of product, impact factor etc.

The roller table can have a single drive linked by line shaft or chain to the rollers or each roller can be individually driven. Individually driven rollers can have rollers driven directly from a motor or via a gearbox which is shatt mounted or has a flexible coupling between roll and gearbox.

The depth of the"shallow"frame can be minimised or eliminated since the loading can be passed directly to the supporting civils. so no heay frames to distribute the loads will be required.

The invention will now be described with reference to the appendez drawings in which: Fig. 1 is a sectional elevation of a roller table supporting a slab : Fig. 2 is a sectional view of the roller table in Fig. 1 ; Fig. 3 is a plan view of Fig. 2, and Fig. 4 is a schematic view of the roller support and load cell In Fig. 1, a slab 1 is supported by a typical roller table comprising seven roller assemblies 2. The slab 1 has passed along the roller table from lett to right and its movement has stopped. When the slab is statiollalv its weight will be determined.

Fig. 2 is a section through the roller table shown in Fi,. 1. through (lie axis of one of the rollers. The slab 1 rests upon solid roller 3. The roller may be tubular. made of discs arrange on a shaft or solid. The roller is mounted in anti-friction bearings (see Fig. 4) incorporated into a housing which is formed into the end of a pivot arm 4. The roller is driven from a motor 9 coupled to a gearbox 8 and finally a flexible coupling 7. The size and type of coupling will depend on the amount of flexing seen by the roller 1 and oad cell 10. The load seen by the coupling should only be radial - any axial load will adversely affect the accuracy of the weighing system. In this version of roller table the motor 9 and gearbox 8 are mounted onto side extensions of drive base frame 5 whilst the loadcells 10 and fixed pivot brackets 12 are directly mounted onto the main longitudinal member of drive base 5. Additional loadcells 10 and pivot brackets 12 are fixed in the same manner to non-drive side base 6 i. e. loadcells 10 and pivot brackets are formed into both base frames 5 and 6 as shown in Fig. 3.

The base frames 5 and 6 are fixed to the foundations 13 by rigid bolts (not shown).

Fig. 4 shows a typical roller 3 mounted in an anti-fi-iction (roller. spherical, plain, etc) bearing 11 to which is located in the end of pivot ai-in 4 The other end of pivot arm 4 is located by pivot pin 14 and anti friction bearing/s 13 into fixed pivot brackets 12. A line joinin (i the centre of rotation of the pivot pin 14 and roller 4 are parallel to the pass line @ of the roller table Directly under the free end of the pivot arm 4 is the loadcell 10 The load cell 10 is mounted to the support bases 5 or 6 when the mountin, face of the load cell 10 to the base 5 or 6 is also parallel to the pass line 15.

As the slab rests on the roller 3 the load/weight is directly transmitted vertically to load cell 10. As the load cell 10 and base frames 5 or 6 can deflect, the passline 15 should be set to accommodate this deflection so tliat only minimal non-vertical loads exist. In reality this deflection can be designed to be less than 1 mm and can be ignored since the setting accuracy and wear will be greater than this amount.

Claims (10)

Claims

1 Apparatus for weighing semi-finished metal products, colnprisillr a roller table having a plurality of transport rolls and load cell means on which the roller table is mounted. characterized in that the load cell means comprises a plurality of load cells each supporting a respective transport roll bearing.

2 Apparatus according to claim 1 characterized in that the hearing housings are mounted on the ends of pivoting arms.

3 Apparatus according to claim 2 characterized in that the pivoting arms are fixed via anti friction bearings and corresponding shafts to a simple "shallow"frame mounted to a fixed support.

4 Apparatus according to either of claims 1 and 2 characterized in that the pivot points of the pivot arms are upstream of the rollers.

5 Apparatus according to any of claims 2 to 4 characterized in that the centre of the pivot point is essentially in the same horizontal plane as the roller centre.

6 Apparatus according to any previous claim characterized in that the roller table has a single drive linked by line shaft or chain to the rollers.

7 Apparatus according to any of claims 1 to 5 characterized in that each roller is individually driven.

8 Apparatus according to claim 7 characterized in that each roller is di-iven directly from a respective motor.

9 Apparatus according to claim 7 characterized in that each roller is driven via a respective gearbox.

10 Apparatus according to claim 9 characterized in that each roller is coupled to its gearbox via a flexible coupling.

I I Apparatus for weighing semi-finished metal products, substautiallv as herein described and illustrated.

10 Apparatus according to claim 9 characterized in that each roller is coupled to its gearbox via a flexible coupling.

11 Apparatus for weighing semi-finished metal products, substantially as herein described and illustrated.

Amendments to the claims have been filed as follows l, Apparatus for weighing semi-finished metal products, comprising a roller table having a plurality of transport rolls and load cell means on which the roller table is mounted, characterized in that the load ccll means comprises a plurality of load cells each supporting a respective transport roll bearing and chose outputs are summed.

2 Apparatus according to claims 1 characterized in that the bearing housings are mounted on the ends of pivoting arms.

3 Apparatus according to claim 2 characterized in that the pivoting arms are fixed via anti friction bearings and corresponding shafts to a simple "shallow" frame mounted to a fixed support.

4 Apparatus according to either of claims 1 and 2 characterized in that tulle pivot points of the pivot arms are upstream of the rollers.

5 Apparatus according to any of claims 2 to 4 characterized in that the centre of the pivot point is essentially in the same horizontal plane as the roller centre.

6 Apparatus according to any previous claim characterized in that the roller table has a single drive linked by line shaft or chain to the rollers.

7 Apparatus according to any of claims 1 to 5 characterized in that each roller is individually driven.

3 Apparatus according to claim 7 characterized in that each roller is driven directly from a respective motor.

9 Apparatus according to claim 7 characterized in that each roller is driven via a respective gearbox.