US3797676A - Adjustable shear bed - Google Patents

Abstract

A table for use in conjunction with a steel shear which is adapted to support a sheet or plate prior to shearing and further, serve as a bed for the pieces sheared. The table is movable between a raised position level with the shear bed and a lower position whereat the table is either level or tipped, at the discretion of the shear operator. The table position is controlled by a pair of rams which rotate shafts which have secured thereto arms which support the table. When the rams are moved through predetermined strokes the table remains level but if one of the rams is actuated through a longer stroke, the table tilts. The table is automatically cycled between the upper and lower positions by operation of the shear.

Description

United States Patent [191 McCarthy I ADJUSTABLE SHEAR BED [76] Inventor: William G. McCarthy, 1235 Westlake Ave., North, Seattle, Wash. 98109 [22] Filed: May 19, 1971 21 App]. No.: 144,824

[52] US. Cl. 214/1 R, 2l4/D1G. 10, 214/701 R, 254/124 [51] Int. Cl. B661: 23/00 [58] Field of Search... l87/8.7l; 214/ 130 R, 130 A, 214/130 B, 130 C, DIG. 10, 1 S, 6 H, 6 BA, 502,512, 394, 1 D; 254/8 R, 8 B, 124;

[451 Mar. 19;, 1974 2,920,773 1/1960 Knabe 298/11 Primary Examiner-Gerald M. Forlenza Assistant Examiner-John Mannix [5 7 ABSTRACT A table for use in conjunction with a steel shear which is adapted to support a sheet or plate prior to shearing and further, serve as a bed for the pieces sheared. The table is movable between a raised position level with the shear bed and a lower position whereat the table is either level or tipped, at the discretion of the shear operator. The table position is controlled by a pair of rams which rotate shafts which have secured thereto arms which support the table. When the rams are moved through predetermined strokes the table remains level but if one of the rams is actuated through a longer stroke, the table tilts. The table is automatically cycled between the upper and lower positions by operation of the shear.

5 Claims, 5 Drawing Figures SHEEY 1 0f 3 JFJIGOH INVENTOR. WILLIAM G. M0 GARTHY QQM ATTORNEYS Pmmmuma m4 3797576 INVENTOR. WILLIAM G. MCCARTHY ATTORNEYS ADJUSTABLE SHEAR BED BACKGROUND OF THE INVENTION In a steel storage warehouse some of the steel is stored in large sheets or plates and then sheared to a desired size following receipt of a purchase order specifying a particular size. The sheets or plates, which are normally heavy and are hard to handle, are sheared in a plate shear normally at least once, although many times a single sheet must be out several times to get the desired size. To get the maximum possible use out of a given size sheet it may be necessary to cut the sheet or plate on perpendicular lines which process is also used to square the sheet or plate for the customer. 7

One of the problems has been in the past that the sheets or plates, as sheared, have either fallen to the floor or onto a table, skids or the like from which they must be removed immediately by crane or other suitable material handling vehicle to clear the shear. A particular problem has been apparent when it was necessary to cut a single sheet or plate more than once. A piece of material handling equipment, as well as an operator have necessarily been required to stand and wait while the shear is performing its function. The equipment was then required to pick up the sheets or plates either from the table upon which it landed or from the floor and transport it around behind the shear, again placing it under control of the operator. As will be readily apparent, whenever it is necessary to have the extra man and material handling equipment to run the shear, the time during which the man and piece of equipment are idle lowers the efficiency of the entire operation.

With the above noted problems in mind it is an object of the present invention to provide a shear table wherein the shear operator has complete control of the location of the table which may cycle with the shear, thereby eliminating the need for an extra man and an extra piece of handling equipment.

It is another object of the present invention to provide a shear table'whereby the operator of the shear may raise a piece of metal previously sheared to a level whereat hemay return the piece and cut it again without using additional equipment.

It is yet another object of the present invention to provide a shear table wherein the table may be controlled enabling the operator of the shear to either stack material upon the table or alternatively to tip the table whereby the material sheared vwill automatically roll to a position distant from the shear where it may be either removed as it is cut or alternatively let stack by itself upon skids or the like.

It is still another object of the present invention to provide a shear table whereby the operator may preselect a mode of operation for the shear table, including that of returning to its uppermost position at the beginning of the shear to support the outer end of the piece being sheared.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is aperspective view of the framework of the shear table with a corner portion of the table removed from its guides for clarity.

FIG. 2 is a plan view of the framework for the subject table showing a hydraulic circuitry necessary for operation.

2 FIG. 3 is a sectional view along line 33 of FIG. 2.

FIG. 4 is an enlarged elevational view shown in the corner portion of the framework with the table in position.

FIG. 5 is a schematic of the circuit diagram rendering the table operational in conjunction with a shear.

DETAILED DESCRIPTION OF THE DRAWINGS As can be seen in FIG. 1 the sheartable comprises a basic rectangular frame having side members 2 and a plurality of reinforcing cross and end members 4. Secured to each corner of the framework is an upstanding trunnion 6. Extending between a pair of the trunnions 6, and parallel to each side 2 of the framework is a shaft 8. Mounted to each of the shafts 8 at either end, adjacent the trunnion 6 is a cylindrical sleeve 10 adapted to turn with the shaft and having a pair of arms 12 extending radially outwardly therefrom. A wheel 14 is journaled for rotation between the outer end of each pair of arms 12 for purposes to be hereinafter described. Likewise secured to shafts 8 for rotation therewith are three cams 9, l1 and 13 adapted to actuate switches 114, 116 and 142 respectively. The interaction of the cams and their associated switches serve as a portion of the controls for the shear table and will be described in detail with respect to the control system. Secured to the framework at opposite ends of one of the sides 2 are a pair of parallel upstanding guide cylinders 16 adapted to restrict the movement of the table to a vertical direction as hereinafter described.

The table, only part of which is shown for clarity,

comprises a rectangular framework 20 having secured therebetween in a direction generally parallel to the shaft 8, a plurality of hollow rods 22 having a plurality of rollers or wheels 24 mounted thereon. The rods 22 have radial ports at the positions at which the wheels 24 will be mounted. The entire line of wheels 24 may thus be greased from one fitting as can be seen in FIG. 4, the lubricant passing through the rods 22 and outwardly to the wheels. The wheels 24 are adapted to be free wheeling such that material located on top of the table is readily movable. The shear operator thus may easily move the sheet around on the table and position it for another shear if necessary and if the table is in a lowered and sloping position as described hereinafter the sheet material will Automaticallyv roll from the table to the next station. As will become apparent hereinafter, the plurality of rollers likewise serves to make the shear operation more efficient since the table has the capability of being positioned at the shear bed level thus providing support for the end of the sheet to be sheared. The additional support in conjunction with the roller surface allows more accurate and rapid placement of the sheet prior to shearing. Mounted between the framework 20, generally below the wheels 24, is a flat plate 26 which serves to prevent objects from falling through the table and damaging the control mechanism within the framework beneath the table.

Extending downwardly from the corners of the table and designed to coincide with the corners of the framework having upstanding posts 16 are a pair of parallel ears 28 having a generally hourglass shaped guide wheel 30 secured therebetween. When the table is in position, the wheel 30 is located between the posts 16 thus restricting the table to movement in a vertical direction and yet not interfering with the removal of the table if such is desired to service the equipment located beneath it.

Referring now to FIG. 2 it can be seen that within the framework there is secured a motor 40 which drives a pump 42 connected to a storage tank 44. The pump is directly attached to tubing 46 which feeds the fluid under pressure to valve 48. The pump is attached directly to outgoing line 46 which feeds the fluid under pressure to solenoid valve 48 which is of the remote control type and directs the fluid to the cylinders hereinafter described. For raising the table to its uppermost position fluid is directed through line 50 through holding valve 52 from which it is transferred through lines 54, 56 to extend cylinders 58, 60 raising the table by means hereinafter described.

To lower the table the fluid is directed from the valve 48 through lines 62 and 67 to cylinder 60 and through holding valve 64 and line 65 to cylinder 58 retracting the rams and thus lowering the table as hereinafter described. Further included within the system is a shock suppressor 70 to take care of any sudden shocks placed upon the table by falling objects and the like without danger of rupturing any of the lines. There is likewise included within the system a series of pilot lines to operate the holding valve when such is necessary, to bleed off any extra fluid which is forced into the shock suppressor by means of a sudden movement of the table and to return any fluid which leaks through the pump to the sump 44. Likewise included is a line which is available to circulate fluid from valve 48 through filter 72 and thus back into the sump whereby when the cylinders 58, 60 are in a hold position the pump will continue to circulate fluid without excess heat build-up or breakdown of the fluid.

Referring now to FIG. 3 it can be seen that the mechanism for operating the table includes the arms 12 immediately adjacent the hydraluic rams 58, 60. The outboard ends of rams 58 and 60 are secured to downwardly extending rigid portions 13 of arms 12 such that movement of the rams causes rotational movement of portions 13 and thereby'sleeves l0, shafts 8 and arms 12. As can be seen the inboard ends of hydraulic rams 58, 60 are secured to an upstanding lug 80 which is in turn secured to a plate 82 extending between two of the reinforcing members 4. The lug 80 is placed at a position which is slightly off center relative to the two frames 2 and the ram 60 has a greater stroke than ram 58 for purposes hereinafter described.

When rams 58 and 60 are in their extended position the arms 12 are vertical and the table is in its uppermost position, at the shear bed level. As can be seen the table when at its upper position is completelyhorizontal. When, through operator direction, the rams are retracted the connection between the lower extension 13 on each of the arms 12 being secured to the shafts of the respective rams 58 and 60 causes the arms 12 to pivot about the axis of shaft 8 thereby lowering the table. As will be hereinafter explained in detail the operator has complete control of the table in that he may lower the table to a horizontal position or alternatively rams 58 and 60 may be retracted completely thus causing the arm 12 associated with ram 60 to pivot further about the axis of rod 60 than does the arm 12 associated with ram 58 thereby causing one side of the table to be lower than the other.-When the rams are fully retracted, material upon the table will move off the table by the force of gravity.

Referring now to FIG. 4 the interrelationship of the framework 2, the shafts 8 mounted between trunnions 6 and the arms 12 which are secured to the shafts and the various parts of the table may more readily be seen. As can be seen in this Fig. the hourglass shaped guide wheel 30 is captured between the two posts 16 which are secured to the framework 2. As noted above the hourglass shaped wheel 30 is mounted for rotation between a pair of downwardly depending ears 28 which are in turn secured from the bottom side of the table. Secured between the two arms 12 is a roller 14 having an outwardly extending annular flange 15. Secured to the underside of plate 26 which underlies the rollers 24 on the table is a reinforcing plate to which is secured a pair of parallel strips 92. The strips 92 are spaced such that they ride upon rollers 14 and flanke the flange 15. The combination of rollers'14, flange 15 assures that the table remains in position once it is in operation.

As will be explained in detail hereinafter referring to FIG. 5 the hereinabove described table, when used in conjunction with a shear greatly increases the versatility and effectiveness of the operator. When the operator signals to the shear to begin operation the table goes to its lowermost position either level or inclined, at the direction of the operator. When the table is at its lowermost position, the shear descends and the piece sheared falls to the table whereat it is either retained, if the table is at a level position, or slides off to a stack if in the inclined position. The shear then returns to its uppermost position and the table likewise raises again such that the operator may feed the sheared material back through the shear for another cut if necessary. Alternatively the table may be locked in the downward position either level or inclined whereby a stack of like material which does not need support at its upper end during the positioning for shear may be sequentially sheared and the sheared portion will stack up on the table or as noted above alternatively roll off the table and to either stack or be removed.

CONTROL SYSTEM Referring now to FIG. 5 the schematic circuit diagram can be seen. The diagram is shown during a normal operating cycle with the table in a raised position and hydraulic pump running. The selector switches are to the automatic and tipped position. The shear operator places a sheet of metal to be sheared beneath the shear blade and actuates the foot switch 100. Actuation of the foot switch energizes relay 102 locking itself energized closing normally open contacts 1020, 102b and 102s and opening normally closed contact 102d actuates the down solenoid 112 of the four-way hydraulic valve. The table then lowers to a tipped position, closing limit switches 1 14 and 116. The closing of limit switch 114 energizes relay 118 which closes normally open contacts 118a, 1l8b and opens l18c. This action by relay 118 opens the foot switch circuit deenergizing relay 102 and the down solenoid and energizes the relay 126. Relay 126 locks itself energized opening normally closed contacts 128 and 130 and closing normally open contacts 126a and 126b. Contact 130 which has a late break circuit in turn deenergizes relay 1 18 after a slight delay. Just prior to the completion of the shear cycle an existing limit switch 132 which is located upon the shear opens momentarily and deenergizes relay 126.

At completion of the shear cycle limit switch 138 closes energizing the up solenoid 140 on the four-way hydraulic valve thus raising the table. When the table is raised the up position limit switch 142 opens deenergizing the up solenoid. The cycle is now complete and ready for another cycle by actuation of the foot switch.

If it is desirable that the table remain in a flat position the operation is identical as that described above with the exception that limit switch 116 energizes relay 118 and the table lowered to the level position.

As explained hereinabove when selector switch is in locked down position the table will lower to either the level or tipped position as determined by the tip-flat selector switch 150 and will remain in this lowered position when the shear cycle is complete. Additional shear cuts can be made while the table is in a locked down position and the system is so designed that the pump may be shut off while the table is in the locked down position thereby preserving the life of the equipment. For safety reasons as well 'as installation, testing and the like there is provided a manual switch 160 to lower the table and another switch 162 to raise the table.

As'hereinabove described, an automated table has been developed to cycle as the shear is operated, on command of the shear foot switch. Integrated with existing plate shear facilities production time is reduced substantially by allowing the operator to continue shearing, depositing plates in a rear storage area, for pick up when desired, or alternatively plates may be re turned to the front of theshear without crane assist or delay.

The electro hydraulic system raises the table to a shear bed level when energized. The shear foot switch then controls the table as well as the shear, the table lowering in advance of the shearing operation to either a tipped or level position, as the shear operator chooses, automatically returning to the shear bed level position at the end of the shearing cycle.

In the tipped position the table gravitates the sheared plates onto skids, trucks or dollies ready for delivery to their next station, the plates sliding off the roller lined table. In the raised position the table furnishes rear support for long plates being positioned for shearing. Should second cuts be required on the sheared plate a pre-select switch, manually set, stops the table at a lowered level position in advance of the shearing operation. The sheared plate falling on the level table is then automatically raised to the shear bed level, and is then in position to be returned through the'shear for second cuts. An additional pre-select switch permits locking the table in either of the lower positions, level or tipped. Should the operator desire to shear several plates before releasing or returning for second cuts the locked level position holds the table level, and below the shear bed, until the desired quantity of plates are sheared. A switch signals the table to raise when desired. In the locked tip position the sheared plates gravity roll off the table as they are sheared.

I claim:

l. A vertically moveable table for handling metallic sheets or the like comprising:

a generally rectangular framework for supporting a table having a plurality of rollers upon its upper surface and enclosing the operating mechanism,

upstanding trunnions at each corner of the framework,

a pair of rotatable shafts, each mounted between a pair of opposed trunnions,

a pair of substantially parallel, radially directed arms mounted to each of the shafts for rotation therewith,

means causing simultaneous rotation of the shafts and the attached arms, one of the shafts being rotated between two discrete positions and the other shaft being rotated between three discrete positions, two of which coincide with the positions of the first shaft, resulting in the outer portion of the arms lying in a horizontal plane, the third position resulting in a plane passing through the outer ends of the-arms, being at an angle to the horizontal,

guide means at one end of said table,

table means having downwardly depending means to cooperate with the guide means, resting upon said arms to permit relative shifting movement of the arm ends along the underside of the table means whereby rotation of the shafts causes raising and lowering of the table which is restricted by the guide means to movement along a vertical path, and

control means for predetermining the movement of the arms to their respective, discrete positions and, thereby, the position of the table.

2. Apparatus as in claim 1 wherein the means for pivoting the rods comprises a pair of hydraulic rams connected to rigid extensions of the arm on the opposite side of the pivot.

3. Apparatus as in claim 1 wherein the guide means comprises a pair of upstanding parallel posts and the cooperating table means comprises a pair of depending ears having an hour-glass shaped roller therebetween designed to cooperate with the posts.

4. Apparatus as in claim 1 wherein the control means includes a first automatic mode wherein the table cyclically moves from its upper position to its lower level position, a second automatic mode wherein the table cyclically moves from its upper position to its lower sloping position and a manual mode wherein an operator controls the position of the table.

5. Apparatus as in claim 4 wherein the automatic mode is actuated in coordination with an associated machine tool.

Claims (5)

1. A vertically moveable table for handling metallic sheets or the like comprising: a generally rectangular framework for supporting a table having a plurality of rollers upon its upper surface and enclosing the operating mechanism, upstanding trunnions at each corner of the framework, a pair of rotatable shafts, each mounted between a pair of opposed trunnions, a pair of substantially parallel, radially directed arms mounted to each of the shafts for rotation therewith, means causing simultaneous rotation of the shafts and the attached arms, one of the shafts being rotated between two discrete positions and the other shaft being rotated between three discrete positions, two of which coincide with the positions of the first shaft, resulting in the outer portion of the arms lying in a horizontal plane, the third position resulting in a plane passing through the outer ends of the arms, being at an angle to the horizontal, guide means at one end of said table, table means having downwardly depending means to cooperate with the guide means, resting upon said arms to permit relative shifting movement of the arm ends along the underside of the table means whereby rotation of the shafts causes raising and lowering of the table which is restricted by the guide means to movement along a vertical path, and control means for predetermining the movement of the arms to their respective, discrete positions and, thereby, the position of the table.

2. Apparatus as in claim 1 wherein the means for pivoting the rods comprises a pair of hydraulic rams connected to rigid extensions of the arm on the opposite side of the pivot.

3. Apparatus as in claim 1 wherein the guide means comprises a pair of upstanding parallel posts and the cooperating table means comprises a pair of depending ears having an hour-glass shaped roller thereBetween designed to cooperate with the posts.

4. Apparatus as in claim 1 wherein the control means includes a first automatic mode wherein the table cyclically moves from its upper position to its lower level position, a second automatic mode wherein the table cyclically moves from its upper position to its lower sloping position and a manual mode wherein an operator controls the position of the table.

5. Apparatus as in claim 4 wherein the automatic mode is actuated in coordination with an associated machine tool.

Images