This invention relates to a vehicle for supporting a pair of horizontal roll assemblies for a rolling mill which are spaced one above the other with the longitudinal axes of the rolls parallel and substantially horizontal.
The rolls of a mill for rolling metal strip have to be changed periodically and it is sometimes desirable to withdraw the horizontal roll assemblies comprising the rolls and their associated bearing chocks out of the mill housing simultaneously and while metal strip is still extending between the rolls. The rolls assemblies are withdrawn from the mill housing on the opposite side to the drive side of the mill and there cannot therefore be any form of connection between the bearing chocks on the rolls at the drive side of the mill. To this end it is usual to employ roll transfer means which comprise a pair of cantilevered sockets arranged one above the other at the same spacing as the roll centres. The sockets grip the adjacent ends of the rolls at the roll change side of the mill and the two roll assemblies are withdrawn in the direction of the length of the rolls simultaneously from the mill housing. Before a pair of new roll assemblies can be introduced into the mill housing by the cantilevered sockets, the old rolls have to be removed from the sockets and displaced from the withdrawal position.
It is an object of the present invention to provide a vehicle for supporting a pair of roll assemblies for a rolling mill when they are spaced one above the other with the longitudinal axes of the rolls parallel and substantially horizontal.
According to the present invention, a support vehicle for a pair of roll assemblies for a rolling mill comprises a wheeled trolley having an upper support member and a lower support member, the upper member being insertable between a pair of roll assemblies spaced apart one above the other and the longitudinal axes of the rolls parallel and substantially horizontal, and providing an upper support surface for receiving the upper of the two roll assemblies and the lower member being insertable beneath the lower of the two assemblies and providing a lower support surface for receiving the lower roll assembly.
After the pair of old roll assemblies have been withdrawn from the mill by the roll transfer means, the support vehicle is brought into a position where the upper and lower members are positioned below the upper roll assembly and the lower roll assembly respectively. The roll assemblies are then lowered together on to the upper and lower support surfaces and the sockets are removed from the ends of the rolls. The support vehicle with the roll assemblies supported on it is then moved away to a position which permits the pair of replacement rolls to be gripped by the cantilevered sockets and introduced simultaneously in the direction of their length into the mill housing.
The trolley may comprise a frame of C-section or alternatively the lower support member may comprise a base of the trolley and the upper support member projects substantially horizontal from a structure extending vertically from the base.
In order that the invention may be more readily understood it will now be described, by way of example only, with reference to the accompanying drawing which is a diagrammatic side elevation of a pair of vehicles each in accordance with the present invention.
Reference numeral 1 indicates the centre line of a rolling mill and on which the horizontal work roll assemblies 2A and 2B of the mill are arranged in vertical spaced apart relation. In order to change the work rolls, while metal strip is still present in the rolling mill, the roll assemblies are separated and the ends of the work rolls on the roll change side of the mill are gripped by means of a pair of sockets (not shown) which are carried in cantilever manner from a transfer car. After the rolls with their bearing chock assemblies have been withdrawn horizontally from the mill housing, it is necessary to support the assemblies individually. To this end a support vehicle 3 is provided. The vehicle shown on the right-hand side of the figure consists of a trolley 5 mounted on wheels 7 so as to be displaceable along a floor level track 9 extending normal to the longitudinal axes of the rolls as they are drawn from the mill housing. The trolley has an upper support member 11 which provides a substantially horizontal upper load support surface 13. The trolley also provides a lower horizontal support surface 17. The member 11 is secured in rigid relation to the trolley by a vertical structure 19 which is on the side of the trolley which is away from the centre line of the mill. A connection member 21 extends downwardly from the trolley into a slot positioned in the floor and a piston-cylinder device 23 is located beneath the floor. One part of the device is fixed and the other is connected to the connection member 21 and when the piston-cylinder device is operated the trolley is displaced along the track.
After the roll assemblies have been withdrawn from the mill housing, the support vehicle is displaced to the left in the FIGURE so that the support member 11 passes beneath the upper roll assembly 2A and the support member 15 passes below the lower roll assembly 2B. The roll assemblies are then lowered slightly so that they are supported on the support surfaces 13 and 17 respectively. The cantilevered sockets are then removed from the ends of the rolls. The support vehicle is then displaced to the right as shown in the FIGURE to a position from which the roll assemblies can be removed from the support vehicle and taken to the roll shop for roll dresssing and maintenance purposes. In the meantime, a pair of replacement roll assemblies 2A' and 2B' are mounted on the upper and lower support surfaces of a further support vehicle 31. This vehicle is mounted on the track 9 and positioned to the left of the centre line of the mill so that, as soon as the old rolls have been displaced away from the centre line on the support vehicle 3, the support vehicle 31 can be displaced into a position where the rolls are aligned with the centre line of the mill. The ends of the rolls are then gripped in the cantilevered sockets, the sockets are raised slightly to lift the assemblies off the support surfaces of the vehicle and the rolls are then introduced into the mill housing. It will be appreciated that the support vehicle 31 is reversed with respect to the vehicle 3 in that the open space between the support members 11 and 5 on the trolley 31 faces the spaces between the same members on the trolley 3.
In the arrangement shown in the FIGURE, the support members 11 and 5 together with the structure 19 form a frame of C-shape construction. As previously indicated, the support member 5 may constitute the base of the trolley with the support member 11 being separate from the base and projecting outwardly from an upstanding support structure 19. Also in the FIGURE the support vehicles are shown as being displaceable at right angles to the direction of movement of the rolls into and out of the mill. This need not be the case, since the vehicles could be displaced diagonally with respect to the direction of withdrawal of the rolls from the mill.
Furthermore, while each vehicle is shown as being displaceable by a hydraulic piston and cylinder device, it could be arranged for each vehicle to have its own drive as for example an electric motor.
Furthermore, it could be arranged for the support surfaces 13 and 5 to be provided by support members which are in the form of jacks or the like so that the surfaces can be raised and lowered slightly with respect to the trolley.