Patent Application
20120104068
The subject matter of this patent application is closely related to that of U.S. Pat. No. 5,937,689 which issued Aug. 17th, 1999.
The following description of this invention will describe an apparatus and method of rolling steel with a triple roller entry guide. It will be noted that the entry guide of this invention is used only when bar is being produced in the rolling process, not when the desired end product is in the form of sheet.
The entry guide of this invention is of the triple roller type, as opposed to the double roller entry guide which was used almost exclusively before the triple roller entry guide was introduced. The triple roller guide is a good deal more robust, wears significantly longer and thus does not lose accuracy due to wear, and because of its longevity in the workplace, it has almost won universal acceptance in the rolling field for rolling steel bar.
The triple jaw guide of the prior art is preset to some certain maximum previously predetermined dimension and all attempts to feed work material which is to be reduced into the guide, which has a diameter of which is slightly greater than this preset dimension at which the guide is set will be resisted by the guide. Although this is fine in theory, it can lead to stoppage in the rolling process when the guide refuses to feed material to the reducing rollers. Furthermore the guide has to be reset for each individual size in the range of bar diameters, resulting in mill down time.
In order to deal with a predetermined size range of bar diameters without resetting the guide it is proposed to make the jaws of the guide more flexible in adjustment so that during a standard run the jaws of the guide function as in prior art guides, that is the three jaws work in the range set for the guide, so that the guides the work product to the reducing rolls of the mill in a normal fashion.
As long as the diameters of the work product stay within a preset value, the rolling process continues and the work product is reduced by the reducing rolls. The jaws of the guide are permitted to open slightly wider than do the jaws of prior art guides, permitting the work product to pass through the guide and be reduced by the reducing rolls of the mill. This saves the time required to change the set-up of the guide and the guide so equipped can now be operated in the previous range (smaller diameter) without any delay in setting the guide to the smaller diameter work product. This saves time when a rolling process is involved. Time, like everything else, counts when a steel mill is down and the management is judged by the number of hours that are lost due to malfunctions of the mill.
It is to deal with such situations such as these that the present invention evolved. The triple guides of the prior art had little tolerance for the acceptance of work product whose diameter was slightly greater than a certain preset value of the guide.
The present invention utilizes a guide which has a funnel shaped opening, has three jaws carrying rollers which are set to guide material of a preset diameter. If, however, the material being fed to the guiding device is of a larger size, such that the diameter of the work product is slightly greater than said preset diameter, the guide will accept the slightly oversized work product and feed it to the reducing rollers anyway. This is made possible by the construction of applicant's device in which the jaws will resistibly open against a certain “preload” force to accommodate the larger diameter in the range of sizes of work product.
The guide of this invention follows the construction of the prior art invention except that a certain “pre load” has been built into the device. The guide of the present invention resistibly accepts material that would not be accepted by the prior art guide device, and the guiding process is allowed to continue even in the presence of larger diameter material in a pre-specified size range to the guide.
The guide of this invention has a funnel shaped admission device which leads the hot work product to a triple jawed guiding device. Here the opening of the jaws of the improved device are set and calibrated as in guides of the prior art, but the jaws may be resistibly “opened” past this position further to accept a work product of a larger size. This is accomplished by the use of a “Pre set spring loaded” member which “kicks in” and allows the jaws of the improved guide to move outwardly and temporarily accept the oversized work product.
The principal of the standard triple jaw guide as shown in
Jaws 20 (of which two are shown) are mounted on pivots 22 which are permanently located in ring 18. Springs 24 assure that jaws 20 always present an opening which is a maximum for the passage of work product there through.
The adjustment of the opening of guide 10 is accomplished by the lateral movement of ring 26 which is mounted on the member 16 and moves to the left or right as determined by the direction of twist of the ring 26. A sloping face 28 on the ring 26 contacts each lock screw 30 of the jaws 20 to adjust the jaws 20 to a selected opening. The original work piece opening may require individual adjustment of the levers or jaws 20 in order to centre the work 12 in the guide 10. This is done by suitably adjusting the lock screws 30 against the sloping face 28 of ring 26. When the jaws 20 of the guide 10 are individually set so that the work piece is centred in guide 10 the guide may be opened or closed by twisting ring 26 until the desired setting of the opening for guide 10 is achieved. It must be remembered that once the jaws of the guide are set, the setting is rigid. This setting remains in the guide until the guide is altered.
Referring now to
A set of springs 116 are mounted in the guide 100 urge the jaws 110 apart to open the jaws 110 to the “maximum” opening permitted by the setting of the guide. Here a set of lock screws 118 are shown contacting ring 120 of guide 100. It is also in this position that the jaws 110 may be adjusted to centre the work product 104 passing through guide 100 by adjustment of lock screws 118.
Ring 120 is made to have a sloping surface 122 for the ends of lock screws 118 to slide upon. Ring 120 is mounted to slidingly fit on surface 124 where ring 120 contacts and surrounds member 102 of the guide 100. Member 106 serves to present a smooth cylindrical outer surface 124 for the lateral motion of ring 120 thereon.
The ring 120 is now set so as to guide the centred work product between rollers 114 and any movement (laterally) of ring 120 will open or close the opening presented by rollers 114 to the work product 104. Rollers 114 will lead the work product 104 directly to the reducing rolls of the mill (not shown).
The method of adding or reducing the “pre loads” to ring 120 is shown in
For instance, it is possible to double the “pre load” supplied by the guide 100 as in
This invention solves the problem of using expensive “down time” for an operating steel mill to adjust guide openings which must be adjusted to accommodate a work product where the diameter temporarily exceeds the opening in the guide. Previously this situation would have entailed shutting down the operation of the mill and adjusting the guide opening. This requires time. It is by the use of this invention that this situation is avoided.
Many modifications and other embodiments of the invention will come to mind of one skilled in the art, having the benefit of the teachings presented in the foregoing description and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed, and that the modifications and embodiments are intended to be included within the scope of the dependent claims.
