US3355926A - Pressure control device for a rolling mill - Google Patents

Description

J. w. OBRIEN 3,355,926

PRESSURE CONTROL DEVICE FOR A ROLLING MILL Dec" 5, 1967 5 Sheets-Sheet 1 Filed Sept. 21, 1964 INVENTOR. JEQEMMA/ 14 owe/EA,"

BY 74 Q 7114:; ATTORNE) Dec. 5, 1967 J, w, 3,355,926

PRESSURE CONTROL DEVICE FOR A ROLLING MILL Filed Sept. 21, 1964 3 Sheets-Sheet 2 X4759; flwim ATTOR/VEV.

Deb. 5, 1967 J. w. O'BRIEN PRESSURE CONTROL DEVICE] FOR A ROLLING MILL Filed Sept. 21, 1964 5 Sheets-Sheet 3 INVENTOR.

JEREMIAH 14 OER/EN ATTORNEY.

United States Patent 3,355,926 PRESSURE CONTROL DEVICE FOR A ROLLING MILL Jeremiah Wagner OBrien, Mount Lebanon, Pa., assignor to United Engineering and Foundry Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Sept. 21, 1964, Ser. No. 397,981 Claims priority, application Great Britain, Oct. 7, 1963, 39,371/63 2 Claims. (Cl. 72-245) ABSTRACT IF THE DISCLOSURE A control valve for a roll adjusting system in a rolling mill having a pair of piston-cylinder assemblies at opposite ends of the roll and a relief valve for each assembly. The control valve permits simultaneous adjustment of the relief valves by means of two sets of gearings mounted on a pair of rotatable and axially displaceable shafts, each of Which is operatively connected to one of the relief valves. One set of gearings is rotated by means of a handwheel to effect rotation of the two shafts in opposite directions and thus to establish unequal outlet pressures from the two valves. The other set of gearing has a locking arrangement which is released when this gearing is to be rotated by a second handwheel to effect rotation of the two shafts in the same direction and thus identically raise or lower the outlet pressure from the two relief valves.

The present invention relates to a control for use in conjunction with a strip-processing device such as a rolling mill or rubber or paper calender and, more particularly, to a control designed to permit processing under a controlled pressure.

In certain types of rolling mill practice, as well as in other similar apparatuses, it is highly advantageous to roll under a controlled pressure as opposed to the more traditional manner of rolling to a specified percentage of reduction of the thickness of the entering material. For example, in temper rolling, to obtain optimum strip metallurgy, it has been found advantageous to control closely the pressure to which the strip being rolled is subject during the process. Also, in the rolling of thin aluminum strip, great advantage can be gained in reducing the strip in a manner in which the pressure of reduction is controlled and kept within a specified narrow range.

Another advantage derived from rolling by pressure is the opportunity of compensating for inherent differential loading on the different sides of the mill. For example, should the rolls on the coupling end, because of their additional Weight, present a particular problem, it is possible to compensate for this unequal load condition so as to obtain uniform pressure across the face of the mill rolls.

It is an object of the present invention to provide a control for use, for example, in conjunction with a rolling mill or like device, whereby piston cylinder assemblies are provided for adjusting the rolls, in which connection the control will provide an arrangement whereby the pressures on either side of the rolls can be predeterminately controlled at a specified value Which can be the same or different and wherein, should differential pressures be desired, these pressures, once established, can be raised and lowered Without disturbing the differential relationship between them.

It is another object of the present invention to provide, in conjunction with at least a pair of relief valves, a control valve mechanism which will permit simultaneous adjustment of the relief valves, whereby the pressure controlled by each valve can be raised and lowered in unison or the controlled pressure varied to a predetermined value and then maintained in this relationship, notwithstanding the pressures may be changed further in unison.

It is another object of this invention to provide in conjunction with a pair of relief valves, a mechanical valve adjustment mechanism for carrying out the immediately preceding object.

These objects, as Well as various other features of the present invention, will be better understood when the following description is read along with the accompanying drawings of which:

FIGURE 1 is a schematic view of a rolling mill, including the hydraulic circuit for the roll adjusting piston cylinder assemblies of the rolling mill,

FIGURE 2 is a plan view, partially in section, of the relief valves and control mechanism forming a part of the hydraulic system illustrated in FIGURE 1,

FIGURE 3 is a sectional view taken along lines III- III of FIGURE 2,

FIGURE 4 is a sectional View taken along lines IV- IV of FIGURE 2, and

FIGURE 5 is a sectional view taken along lines V-V of FIGURE 2.

With reference to the drawings and first to FIGURE 1., there is illustrated in schematic form a 4-high strip rolling mill 11 comprising a pair of Work rolls 12 which are supported in the usual manner by individual backup rolls 13, the rolls being received in housings 14 and 15 of the mill 11. Reference to the various other well-known components of the rolling mill will not be made since such is not deemed necessary to understand the present invention. It will be noted with respect to the mill, however, that at the bottom of the housings 14 and 15, there are provided for adjusting the two lower rolls 12 and 13, individual piston cylinder assemblies 16 and 17. These piston cylinder assemblies, as illustrated in FIG- URE 1, are single-acting assemblies in which connection at their bottoms there are provided ports 18 to which hydraulic lines 19 and 20 are connected. As shown, the lines 19 and 20 are connected to separate two-way pumps 21 which are connected, in turn, to a common electrical motor 22. The lines 19 and 2d are also separately connected to separate relief valves 23 and 24, respectively, the relief valves, as shown, having a common drain line 25 which is led into a tank 26. Connected to a common side of the relief valves 23 and 24, there is a dual valve control unit 27. As FIGURE 1 shows, the relief valve 23 services the piston cylinder assembly 16 while the valve 24 services the assembly 17.

It will be appreciated that While the hydraulic system has been purposely kept simple to facilitate a quick understanding of the illustrated embodiment of the present invention, the hydraulic system will include various other components, such as, two-way valves, pressure gauges, oil coolers, etc. depending on the particular installation. The relief valves 23 and 24 are themselves a well-known commercial unit. The particular valves illustrated are manufactured by Vickers 1110., Detroit, Michigan, United States of America, the basic components and operation being clearly set forth in US. Patent No. 2,388,820 which issued to G. C. Bonnell on November 13, 1945, entitled Relief Valve for Power Transmissions.

As shown in FIGURE 3, and in identifying the salient components of the valves 23 and 24, they each consist of a housing 31 which has in its upper portion a pressure control chamber 32 into which there is received a tension spring 33 for urging a plug 34; into an orifice 35. The other end of the spring is connected to a rod 36 of the dual valve control unit 27 and to which more particular reference Will be made hereinafter. The orifice 35 communicates with a chamber 37 formed in the housing 31 into which chamber there is received at the lower end of the housing an axially movable piston 38. The one end of the piston 33 engages a seat 3') against which it is urged by a spring 41 received in the housing 31. Communicating with the chambers 32 and 37 is a third chamber 42, a fourth chamber 43 is actually formed at the right-hand side of the piston 38 which communicates with the chamber 37 by a port 43a formed in the piston 38. The valve at the base, as shown, has three ports, namely 44, 45, 46 in which connection the port 45 is the pressure port, the port 46 the return port and the port 44 the controlled vent or blocked port.

In operation, when the pressure in the chambers 37 and 43 are balanced and the piston 38 is seated against the seat 39, no fluid will escape through the orifice 35, assuming that the force of the springs 33 is greater than the balance pressure in the chambers 37 and 43. When the pressure in the chamber 37 increases in excess of the resistance offered by the spring 33, then the fluid is allowed to escape through the orifice 35 so that the pressure in the chamber 37 will be less than the pressure in the chamber 43. This will allow the piston 38 to move toward the left as one views FIGURE 3 against the resistance offered by the spring 41 and the end will free itself from the seat 39, thereby allowing fluid to be discharged into the chamber 42. Also, the fluid that passes through the orifice 35 will find its way into the chamber 42 and be discharged from the return port 46.

With reference now FIGURES 2, 3, 4 and which relate, as previously mentioned, to the dual valve control unit 27, this unit consists of a housing 51 which, as FIG- URE 2 shows, is carried by a base 52 and to which it is secured by four bolts 53 and by which means it is adjustable toward and away from the relief valves 23 and 24.

In first referring to the gear train that provides for simultaneous and equal adjustment of the relief valves 23 and 24, reference will be made to FIGURE 2 where there is shown a hand wheel 56 which is rotatably supported in the housing 51 and to which there is connected a long rotatable shaft 57 that extends entirely through the housing 51. The opposite end of the shaft 57 is connected by an adapter 58 to the shaft 36 of the valve 24. To the shaft 57 at the end adjacent to the hand wheel 56 there is secured a gear 61 which is connected to the shaft by a key 62, the arrangement being such as to assure that there will be no relative rotational movement between the gear 61 and the shaft, but the shaft will be allowed to move axially relative to the gear 61. Except for the hand wheel, an identical shaft-gear arrangement is provided at the other side of the housing 51 where, as shown in FIGURE 2, there is provided a rotatable shaft 63 which extends through the housing 51 and has at its other end an adapter 64 which connects the shaft 63 tothe shaft 36 of the relief valve 23. The shaft 63, at the end adjacent the hand wheel 56, has secured thereto a gear 65 which is connected to the shaft 63 by a key 66, the arrangement being such that relative rotational movement between the gear 65 and the shaft 63 is prohibited, but the shaft is allowed to move axially relative to the gear 65. In meshing relationship with both of the gears 61 and 65 there is a pinion 67 located so that its axis falls below the common plane containing the axes of the gears 61 and 65 which relationship is best shown in FIGURE 5. The pinion 67, as shown in FIGURE 4, is provided with end bushings 68 and 69 which are received in the housing 51, the pinion 6'7 being supported by the bearings by means of a non-rotatable shaft 70.

As shown in FIGURES 4 and 5, a latch is provided for preventing rotation of the gears 61 and 65 and in this connection there is provided a non-rotatable shaft 71, which at its lower end is provided with a portion 72 having a series of teeth that engage with the upper teeth of the pinion 67. Above the portion 72, there is provided two axially spacedapart collars 73 between which there is arranged a spring 74 which tends to urge the shaft 71 downwardly. The upper portion of the shaft 71 that protrudes through the housing 51 is connected to a lever 75 which is arranged substantially perpendicular to the axis of the shaft 71. The lever 75 is connected toward its one end to a stand 76 which is connected to the housing 51. The lever has a handle 78 which on the depression thereof causes the shaft to raise against the force of the spring 74 to disengage the teeth of the shaft portion 72 from the teeth of the pinion 67. Of course, once the handle 78 is released, the spring will force downwardly the shaft 71 into its locking position.

In now referring to the gear train that provides for adjustment of the valves 23 and 24 in opposite directions, reference again is made to FIGURE 2. It will be noted with respect to the shafts 57 and 63 that they are provided with threaded portions 81, 82, respectively, and in threaded engagement therewith are worm gear wheels 33 and 84, respectively, these gear wheels meshing with a common Worm that extends in a vertical direction relative to the axes of the shafts 5'7 and 63. As shown in FIGURE 4, the worm 85 is secured to a shaft 86 which is rotatably received in the housing 51 in bushings 87 and 88 retained in the housing by keeper plates 82, and 91. At the top of the shaft 86, there is provided a hand wheel 92 by which means the shaft 86 and worm S5 and, hence, the gears 84 and 83 are rotated, the latter being rotated in opposite directions to each other whereby causing the shafts 57 and 63 to move axially in opposite directions through the agency of their threaded portions 81 and 82.

Associated with the relief valves 23 and 24 are pressure gauges 93 and 94 arranged in close proximity to the valve control unit 27 so that the operator will be apprised at all times of the pressures in the two cylinders 16 and 17.

A brief description of the operation of the present invention will now be given with respect to the control of the pressure in the piston cylinder assemblies 16 and 17 of the mill 11. Assuming that the relative positions of the gearing are such as to impose identical compression forces on the two springs 33 of the relief valves 23 and 24 and it is desired to raise the pressure, yet maintaining equal the pressure in the lines 19 and 20, then, in that event, the latch is released to permit rotation of the gears 61 and 65 by depressing the handle 78 to raise the shaft 71, whereby the teeth of the pinion 67 are disengaged from the teeth of the portion 72 of the shaft 71. After this the hand wheels 56 may be rotated which'will rotate the gears 61 and 65 in unison causing similar rotation of the shafts 57 and 63 whereby the rods 36 of the relief valves ..3 and 24 will be d'splaced an equal amount commensurate with the new desired pressures, as indicated in the gauges 93 and 94.

Should it be desired to operate under a differential pres sure condition whereby, for example, only the pressure in the piston cylinder assembly 17 is to be increased, with the gears 61 and 65 in their locked position, the hand wheel $2 will be rotated the desired amount to obtain the desired differential pressure condition as reflected by the gauges 93 and 94 associated with the relief valves 23 and 24. Of course, it may be necessary to again operate the hand wheel 56 to obtain the precise pressure for each cylinder 16 and 17.

In accordance with the provisions of the patent statutes, I have explained the principle and operation of my invention and have illustrated and described what I consider to represent the best embodiment thereof. However, I desire to have it understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. In a fluid control system for a rolling mill or the like apparatus having at least a pair of rolls, including apair of piston cylinder assemblies arranged at the opposite ends of one of the rolls of the mill to cause said one 5 roll to move towards and away from the other roll of the pair, the improvement comprising:

a relief valve connected to each of said piston cylinder assemblies, including displaceable members for controlling the pressure of the fluid delivered to said piston cylinder assemblies,

said displaceable members being received in pressure control chambers formed in said valves which include spring-biased control plugs,

a pair of rotatably mounted, axially displaceable shafts, one of said shafts being connected to one of said control plugs and the other shaft being connected to the other of said control plugs,

first gearing mounted on said shafts for causing rotation thereof,

a Worm arranged to interconnect said shafts through said first gearing,

means for rotating said first gearing and worm to effect rotation of said shafts in opposite directions to establish an unequaled output pressure of the fluid delivered from said valves,

second gearing mounted on said shafts for causing rotation thereof,

a pinion arranged to interconnect said shafts through said second gearing,

cluding a locking means for preventing rotation of one of said gearing, and

means for rendering said locking means inoperative to allow rotation of said one gearing.

References Cited UNITED STATES PATENTS 581,078 4/ 1897 Menne 72-245 2,678,465 5/ 1954 Schnook et al. 72--245 3,024,679 3/1962 Fox 72245 3,039,513 6/ 1962 Lasiewicz 728 FOREIGN PATENTS 647,606 12/1950 Great Britain.

CHARLES W. LANHAM, Primary Examiner. 25 A. RUDERMAN, Assistant Examiner.

Claims (1)

1. IN A FLUID CONTROL SYSTEM FOR A ROLLING MILL OR THE LIKE APPARATUS HAVING AT LEAST A PAIR OF ROLLS, INCLUDING A PAIR OF PISTON CYLINDER ASSEMBLIES ARRANGED AT THE OPPOSITE ENDS OF ONE OF THE ROLLS OF THE MILL TO CAUSE SAID ONE ROLL TO MOVE TOWARDS AND AWAY FROM THE OTHER ROLL OF THE PAIR, THE IMPROVEMENT COMPRISING: A RELIEF VALUE CONNECTED TO EACH OF SAID PISTON CYLINDER ASSEMMBLIES, INCLUDING DISPLACEABLE MEMBERS FOR CONTROLLING THE PRESSURE OF THE FLUID DELIVERED TO SAID PISTON CYLINDER ASSEMBLIES, SAID DISPLACEABLE MEMBERS BEING RECEIVED IN PRESSURE CONTROL CHAMBERS FORMED IN SAID VALVES WHICH INCLUDE SPRING-BIASED CONTROL PLUGS, A PAIR OF ROTATABLY MOUNTED, AXIALLY DISPLACEABLE SHAFTS, ONE OF SAID SHAFTS BEING CONNECTED TO ONE OF SAID CONTROL PLUGS AND THE OTHER SHAFT BEING CONNECTED TO THE OTHER OF SAID CONTROL PLUGS, FIRST GEARING MOUNTED ON SAID SHAFTS FOR CAUSING ROTATION THEREOF, WORM ARRANGED TO INTERCONNECT SAID SHAFTS THROUGH SAID FIRST GEARING,

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