CLAMP FOR ROLLING MILL ROLL STAND

Abstract

A clamp for releasably securing a rolling mill roll stand on a support structure, comprises a tubular housing adapted to be secured to the support structure. A piston subdivides the interior of the housing into front and rear chambers. A clamping jaw projects forwardly from the piston through an open front end of the housing. The piston is reciprocally movable between a locked position at which the clamping jaw engages the roll stand, and an unlocked position at which the clamping jaw is disengaged from the roll stand. Resilient elements act in the rear chamber to exert a locking force urging the piston into its locked position, and pressurized fluid acts in the front chamber to overcome the resilient locking force when unlocking the clamp.

Description

BACKGROUND

1. Field

Embodiments of the present invention relate to clamps for securing rolling mill roll stands to support structures.

2. Description of Related Art

Roll stand clamps typically have clamping jaws operated by the pistons of double acting hydraulic cylinders. The clamps operate in hostile environments in which they are constantly exposed to cooling water containing abrasive mill scale and other entrained contaminants. Over time, ingress of these elements gradually prevents the piston rods from sliding smoothly in the cylinders, to the point where the clamps no longer function. Clamp malfunctions can complicate removal and replacement of roll stands, thus prolonging mill down time. Also, in the event of a loss of hydraulic pressure, the clamps lose their ability to reliably secure the roll stands in place along the mill pass line.

SUMMARY

Broadly stated, embodiments of the present invention address the problems described above by providing an improved roll stamp clamp having enhanced external guards and internal seals designed to effectively prevent ingress of contaminants.

In exemplary embodiments of the present invention, the clamp is designed as a cartridge that can readily be inserted into and removed from the stand support structure.

In a preferred exemplary embodiment of the present invention, the clamp comprises a tubular housing having a cylindrical interior extending along a central axis from a closed rear end to an open front end. A piston subdivides the housing interior into front and rear chambers. A clamping jaw projects forwardly from the piston through the open front end of the housing. A resilient means acts in the rear chamber to exert a locking force urging the piston and the clamping jaw into a locked position. In order to unlock the clamp, a hydraulic fluid means acts in the front chamber to overcome the resilient locking force of the resilient means.

As herein employed, “resilient means” means enclosed or self contained mechanisms capable of exerting closure or locking forces without the aid of externally generated power sources.

In exemplary embodiments of the present invention, the rear chamber of the clamp is filled with a liquid lubricant.

The resilient means may comprise at least one spring, and preferably a plurality of stacked Belleville springs, axially confined between the closed rear end of the housing and the piston. Gas charged openings may also serve as resilient means.

In other exemplary embodiments of the present invention, an expandable bellows and/or cylindrical shroud serve to prevent ingress of cooling water and entrained contaminants.

These and other objects, features and advantages of the present invention will become more apparent upon reading the following detailed description in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a rolling mill roll stand secured to an underlying support structure by a clamp in accordance with an exemplary embodiment of the present invention;

FIG. 2 is an enlarged front view of the clamp shown in FIG. 1;

FIG. 3 is a perspective view of a clamp in accordance with an exemplary embodiment of the present invention;

FIGS. 4 and 5 are sectional views taken respectively along lines 4-4 and 5-5 of FIG. 2, and showing a clamp in accordance with an exemplary embodiment of the present invention in a locked position;

FIG. 6 is a view similar to FIG. 5 showing the clamp in an unlocked position; and

FIG. 7 is a perspective view showing a clamp in accordance with an exemplary embodiment of the present invention withdrawn from roll stand support structure.

DETAILED DESCRIPTION

The components described hereinafter making up the various embodiments are intended to be illustrative and not restrictive. Many suitable components that would perform the same or a similar function as well as the materials described herein are intended to be embraced within the scope of embodiments of the present invention.

Referring now to the figures, wherein like reference numerals represent like parts throughout the views, embodiments of the present invention will be described in detail.

With reference initially to FIG. 1. a rolling mill roll stand 10 has a pair of work rolls 12 supported between housing posts 14 interconnected by bridging elements 16.

The posts 14 project upwardly from a base 18 secured to a support structure 20 by a clamp 22 in accordance with an exemplary embodiment of the present invention.

With reference additionally to FIGS. 2-6, it will be seen that the clamp 22 comprises a tubular housing 24 having a cylindrical interior extending along a central axis “A”. A rear end of the housing 24 is closed by an end plate 26 secured to the housing by bolts 28 or the like. A front end of the housing is open and defined by a circular collar 30 lined with an annular insert 31.

As depicted in FIG. 7, the cylindrical housing is in effect a cartridge designed for inserting into and removal from a cylindrical opening 32 in the support structure 20.

A piston 34 subdivides the interior of the housing 24 into front and rear chambers 34, 38.

A clamping jaw 40 projects forwardly from the piston 34 through the annular insert 31 at the open end of the housing 24. The piston 34 is reciprocally movable along axis A between a locked position engaging a component 42 of the roll stand base, as shown in FIGS. 4 and 5, and an unlocked position at which the clamping jaw is removed from the component 42, as shown in FIG. 6.

Preferably, and again as shown in FIG. 6, the clamping jaw 40 has a beveled clamping surface 40′ configured and dimensioned to coact with a correspondingly beveled surface 42′ on the roll stand component 42.

A resilient means acts in the rear chamber 38 to exert a locking force urging the piston 34 and the clamping jaw 40 forwardly into the locked position. The resilient means comprises at least one spring, and preferably comprises a plurality of Bellville springs 44 confined between the end plate 26 and the piston 34 in a stacked arrangement along axis A.

In order to unlock the clamp 22, a fluid means acts in the front chamber 36 to overcome the resilient locking force of the resilient means in the rear chamber 38. As can best be seen in FIG. 5, the fluid means may comprise pressurized hydraulic fluid introduced into the front chamber 36 via a passageway 46 in the wall of the housing 24.

In order to exclude cooling water and entrained contaminants from penetrating into the interior of the housing 24, an expendable bellows 48 is connected at opposite ends to the housing and the clamping jaw 40.

Additionally, a cylindrical shroud 50 projects forwardly from the housing 24 to surround the bellows 48.

Preferably, a first O-ring seal 52 is positioned on the piston for sealing engagement with the interior surface of the housing 24. A second O-ring seal 54 may be positioned within the annular insert 31 for sealing engagement with a cylindrical section of the clamping jaw 40.

A piston rod 56 extends rearwardly from the piston 34. The piston rod is slidebly received in an annular guide 58 supported by the end plate 26. A guide pin 60 projects internally from the end plate 26 and is slidebly received in a blind bore 62 in the rear end of the piston rod 56.

Preferably, the rear chamber 38 is filled with a liquid lubricant received via a port 64 in the end plate 26 from an external storage tank 66. The liquid filled rear chamber further serves to exclude contaminants from the interior of the housing 24.

In light of the foregoing, it will now be understood that the clamp 22 of the present invention operates in a “fail safe” mode because of its enclosed or self contained resilient means, which will reliable exert a clamping force regardless of any type of power loss or failure of ancillary equipment.

While exemplary embodiments of the invention have been disclosed, modification, additions and deletions can be made without departing from the spirit and scope of the invention and its equivalents, as set forth in the following claims.

Claims

1. A clamp for releasably securing a rolling mill roll stand on a support structure, said clamp comprising:

a tubular housing adapted to be secured to said support structure, said housing having a cylindrical interior extending along a central axis between a closed rear end and an open front end;

a piston subdividing the interior of said housing into front and rear chambers;

a clamping jaw projecting forwardly from said piston through the open front end of said housing, said piston being reciprocally movable along said axis between a locked position at which said clamping jaw engages said roll stand, and an unlocked position at which said clamping jaw is disengaged from said roll stand;

resilient means acting in said rear chamber to exert a locking force urging said piston into said locked position; and

fluid means acting in said front chamber to overcome said locking force to thereby urge said piston into said unlocked position.

2. The clamp of claim 1 wherein said rear chamber is filled with a liquid lubricant.

3. The clamp of claim 2 wherein said rear chamber is connected to an external source containing a supply of said lubricant.

4. The clamp of claim 1 wherein said resilient means comprises at least one spring axially confined between the closed rear end of said housing and said piston.

5. The clamp of claim 4 wherein said resilient means comprises a plurality of Belleville springs in a stacked arrangement along said axis.

6. The clamp of claim 1 wherein the open front end of said housing is defined by an annular collar, and wherein said clamping jaw has a cylindrical body projecting through said collar.

7. The clamp of claim 1 further comprising an expandable bellows connected at opposite ends respectively to said housing and said clamping jaw.

8. The clamp of claim 1 further comprising a piston rod extending rearwardly from said piston, said piston rod being slidably received in an annular guide at the closed rear end of said housing.

9. The clamp of claim 7 further comprising a cylindrical shroud projecting forwardly from the open end of said housing, said bellows being surrounded by said shroud.

10. The clamp of claim 8 further comprising a guide pin projecting interiorly from the closed rear end of said housing, said guide pin being slidably received in a blind bore in said piston rod.

11. The clamp of claim 1 wherein said housing has a cylindrical wall surrounded said interior, and wherein a first O-ring seal is positioned on said piston for sealing contact with said wall.

12. The clamp of claim 6 further comprising a second O-ring seal is positioned within said annular collar for sealing contact with the cylindrical body of said clamping jaw.

13. The clamp of claim 1 wherein said housing is configured and adapted for insertion into an opening in said support structure.

14. The clamp of claim 1 wherein said fluid means comprises a pressurized liquid introduced into said front chamber.

15. The clamp of claim 1 wherein said clamping jaw includes a beveled clamping surface configured and dimensioned to coact with a correspondingly beveled surface on said roll stand.

16. A clamp for releasably fixing a rolling mill roll stand on a support structure, said clamp comprising:

a tubular housing adapted to be secured to said support structure, said housing having a cylindrical interior extending along a central axis between a closed rear end and an open front end;

a piston subdividing the interior of said housing into front and rear chambers, said rear chamber being filled with a liquid lubricant and being in communication with an external supply of said lubricant;

a clamping jaw projecting forwardly from said piston through the open front end of said housing, said piston being reciprocally movable along said axis between a locked position at which said clamping jaw engages said roll stand, and an unlocked position at which said clamping jaw is disengaged from said roll stand;

resilient means acting in said rear chamber to exert a locking force urging said piston into said locked position, said resilient means comprising a plurality of Belleville springs in a stacked arrangement along said central axis; and

fluid means acting in said front chamber to overcome said locking force to thereby urge said piston into said unlocked position.