US 3820367 A
Description (OCR text may contain errors)
United States Patent [191 Kline [451 June 28, 1974 POWER FEED AND UNCOILER FOR HOT FORGING MACHINES OR THE LIKE  Inventor: 'Gaylen 0. Kline, Tiffin, Ohio  Assignee: The National Machinery Company,
Primary Examiner-Charles W. Lanham Assistant ExaminerRobert M. Rogers Attorney, Agent, or FirmMcNenny, Farrington, Pearne & Gordon [5 7] ABSTRACT A hot forging machine system is disclosed in which stock in coil form having a first radius of curvature is supplied to the machine. The stock feed includes a preliminary powered straightener which partially straightens the coiled stock and feeds it into a loop. The intermittently driven forging machine feed rolls pull the stock from the loop through a secondary straightener to complete the straightening operation and through a heater which heats the stock before it reaches the forging machine. Sensing means determine the size of the loop and control the rate of operation of the preliminary straightener to maintain the size of the loop within predetermined limits. Undesirable elongation of the heated stock does not occur, since the force required to intermittently feed the stock through the secondary straightener is not sufficiently great to cause such elongation.
16 Claims, 4 Drawing Figures POWER FEED AND UNCOILER FOR IIOT FORGING MACHINES OR THE LIKE BACKGROUND OF THE INVENTION PRIOR ART Hot forging machines such as those disclosed in the US. Pat. Nos. 2,698,950 and 2,698,951, both issued Jan. 11, 1955, have been used for the manufacture of nuts from bar stock. In such machines, successive lengths of straight bars are pulled by feed rolls through a heating furnace and are intermittently advanced into the cutoff station of the machine. In such machines, the slugs or blanks are cut from the forward end of the stock and are subsequently forged to the desired shape.
In cold forging machines of similar type in which stock is intermittently fed into a cutoff station and cut into slugs or blanks for subsequent cold working, it has been common to supply the machine with stock in coil form so that longer pieces of stock can be supplied to the machine. Examples of such cold forging machines are illustrated in the U87 Pat. Nos. 2,219,811 issued Oct. 29, 1940; 2,646,102 issued July 21, 1953; and 2,664,250 issued Dec. 29, 1953.
lnspite of the knowledge that savings could be realized when the stock supplied to an automatic machine is in the longer length of the coil form, it has been the practice to supply hot forging machines, particularly in the larger machines, with straight lengths of stock which are necessarily much shorter than stock in coil form. This practice of using straight bars of stock has continued to a considerable extent because the heated stock, often having a temperature in the order of 1,800 F., cannot be subjected to sufficient tensile stress to accomplish the straightening of the stock required when the stock initially is in coil form.
SUMMARY OF THE INVENTION In the illustrated machine system incorporating the present invention, a hot forging machine is supplied with coiled stock. The system is arranged so that the hot stock is not subjected to sufficient tensile stress to cause undesirable elongation or the like. In the illustrated embodiment of this invention, the coiled stock passes first through a powered straightener arranged to perform a partial straightening operation in which the radius of curvature of the stock is increased a substantial amount. The partially straightened stock then moves along a relatively large radiused loop to a secondary straightener which completes the straightening operation.
From the secondary straightener, the straightened stock passes through a heating furnace and into the cutoff station of the forging machine. The force for pulling the stock through the secondary straightener and furnace is supplied by the machine feed roll and is transmitted through the heated stock. However, because the amount of straightening occurring at the secondary straightener is relatively small, the tensile forces which must be carried through the heated stock are sufficiently small so that undesirable elongation of the heated stock does not occur. The operation of the preliminary straightener is controlled by a sensor which detennines the size of the loop between the two straighteners and maintains such loop within predetermined limits.
Means are also provided to cut the stock between the secondary straightener and the furnace and to feed the severed stock to a storage rack when the operation of the machine is terminated.
In a second illustrated embodiment, the secondary straightener is powered to complete the straightening of the stock and only the feeding force is supplied through the heated section of stock.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of the entire feed system in accordance with one embodiment of this invention for feeding coiled stock to a hot forging machine or the like;
FIG. 2 is a schematic illustration of a second form of secondary straightener which may be used in some instances;
- FIG. 3 is a fragmentary plan view illustrating a preliminary straightener which may be used with a coil of stock positioned with a horizontal axis; and
FIG. 4 is a side elevation of the preliminary straightener illustrated in FIG. 3.
DETAILED DESCRIPTION OF THE DRAWINGS In the drawings, the various components of the feed system in accordance with this invention are schematically illustrated without full structural detail, since the system components may be conventional components known to those skilled in the art. FIG. 1 illustrates in plan view the overall system in accordance with one embodiment of this invention. In this embodiment, the stock for the system is supplied as a coil 10 having its axis vertical. The stock is pulled off the coil by powered feed rolls 11 and is pushed through a preliminary straightener 12 from which it is guided along a semicircular loop 13 to a secondary straightener 14. From the secondary straightener, the straight stock passes through a heating furnace 16 to double feed rolls 17 on a hot forging machine 18.
Both illustrated straighteners are of the type that includes a series of rollers which cooperate to straighten the stock. The double feed rolls 17 are intermittently driven in timed relation to the operation of the machine 18 and operate to supply the stock to a cutoff station at 19 wherein slugs or blanks are sheared from the forward end of the hot stock. Such slugs are subsequently hot forged to the required shape within the hot forging.
machine 18. An intermittent drive is required for the double feed rolls 17 to properly supply the stock to the cutoff station. In practice, the stock is fed into engagement with a stock stop and the feed is then terminated while the shear operates to cut the blank or slug from the stock. After the shearing operation, the feed rolls again operate to move the stock forward until it again engages the stock stop. Therefore, the feeding of the stock to the machine is intermittent.
With the preferred embodiment of this invention, the feed rolls 11 are not driven intermittently even though the stock is intermittently removed from the loop 13. Instead, the feed rolls 11 are driven continuously at a speed controlled by a sensor 21 which operates to insure that the size of the loop 13 is maintained within predetermined limits. The sensor is provided with a roller 20 which engages the stock at about the midpoint of the loop and is carried by an arm 22 pivoted on the sensor 21.
If the rate of stock fed into the machine is greater than the rate of feed of stock by the rollers 11, the arm 22 rotates in a clockwise direction from the full line position toward the phantom position 22a. When this occurs, the speed of the feed rolls 11 is increased to supply the stock to the loop at a greater rate. On the other hand, if the rate of removal of stock from the loop is less than the rate of which the stock is supplied to the loop by the feed rolls 11, the arm 22 rotates in an anticlockwise direction toward the position 22b and causes the feed rolls 11 to slow down. The sensor 21 also operates to stop the feed rolls 11 if the arm 22 moves to the position 22b to automatically prevent continued operation of the feed rolls 11 when the machine 18 is stopped.
The motor 23 for driving the feed rolls 11 is preferably a variable speed electric motor connected to and controlled by the sensor 21 as schematically illustrated by the dotted line 24. Horizontally extending support rolls 26 are provided at suitable locations to support the loop 13 while allowing for the loop to be shortened or lengthened. Vertical rollers 25 are located near the ends of the loop to position the loop.
When a piece of stock is initially supplied to the machine, the end of the stock is placed between the feed rolls 1 l and is pushed by such rolls through the straightener 12 around the loop 13 and to the secondary straightener 14. A motor 27 is connected to drive the secondary feed rolls 14 so that the end of the stock can be driven through the secondary straightener and the furnace 16 to the intermittently driven feed rolls 17. Once the end of the stock is engaged by the feed rolls 17 of the machine 18, the motor 27 is disengaged and the feed rolls 17 provide the necessary force to pull the stock through the secondary straightener 14. The force required to intermittently pull the stock through the secondary straightener 14 is not excessive since the amount of straightening occurring at the secondary straightener is small. The operation continues with the sensor 21 controlling the feed of the feed rolls 11 to insure that the amount of stock supplied by the feed rolls 11 is substantially equal to the amount of stock removed from the loop by the intermittently driven feed rolls 17.
The furnace .16 is sized and controlled so that during normal operation of the machine the stock reaching the cutoff station is at the desired temperature. Therefore, the furnace 16 is sized and controlled so that the stock passing through the furnace is heated to the required temperature in the period of time it is contained within the furnace while moving through the furnace at the normal operating-speed.
In some instances when the operation of the machine is terminated for any reason while stock remains in the furnace 16, it is necessary to remove the stock from the furnace to prevent it from becoming excessively heated. A shear 31 and feed rolls 32 powered by a motor 33 are utilized to remove stock from the furnace 16 when the machine operation is terminated. When it is necessary to remove the stock, the shear 31 is operated to cut the stock at 34. The secondary straightener 14 is then lowered below the axis of the piece of stock 36 between the cutoff station 19 and the shear 31. The feed rolls 32 are then operated to move the piece 36 of stock to the left as viewed in FIG. 1 to a storage rack indicated generally at 37. The storage rack 37 is provided with an idler roll 38 and powered rollers 39 and 41 which support the stock as it moves into the storage rack. The powered rollers 39 and 41 continue to move the stock after the end moves out of the rolls 32 until it arrives at the position of the piece 36a. During the initial removal of the stock from the machine and the heater, the intermittently driven feed rolls are opened to allow removal of the stock. When the stock engages a limit switch 42, the motor 43 driving the rolls 41 and 39 is stopped. Rack members 44 are then raised to lift the piece of stock from the rolls so that the piece rolls to a position at 36b where it is cooled.
When it is desired to use the piece of stock, the rack members 44 are lowered to redeposit the cool piece on the rollers 38, 39, and 41. The motor 43 is then energized while the secondary straightener is in the lowered position to move the piece of stock back to the feed rolls 32 which in turn move the stock through the furnace 16 into the intermittently driven feed rolls 17. These intermittently driven feed rolls then operate to carry the heated stock into the machine where it is used.
In some instances where the force required to pull the stock through the secondary straightener is sufficiently high to produce elongation of the heated stock, a straightener of the type illustrated in FIG. 2 may be utilized in the system of FIG. 1, in place of the secondary roller straightener 1.4. Such a situation can exist for example where the required forging temperature must be particularly high or when larger diameter stock is required. In FIG. 2, similar reference numerals are used for corresponding elements of the embodiment of FIG. 1, but a prime is added to indicate that reference is made to the second embodiment. In this embodiment, the stock is again partially straightened by a first power driven straightener and then moves around a loop 13. The stock from the loop 13' passes through a secondary straightener 14 past a cutter or shear 31, feed rolls 32', and to the furnace 16'. The straightener 14', however, does not require as much force to move the stock through the straightener as the form of straightener illustrated in FIG. 1 since the power for straightening is supplied through a powered arm 54. In the straightener l4, spaced opposed pairs of support rolls 51' and 52' engage the stock at spaced locations along the stock. A roller 53 is mounted on the arm 54' pivoted at 56' to engage the stock between the support rollers 51 and 52'. The arm 54' is operated by a drive link 58' from the main machine drive in timed relation to the operation of the machine. In practice, the arm is rotated in an anitclockwise direction from the position illustrated before the feed rolls of the machine feed the stock forward. The machine feed rolls then feed an unstraightened length of stock past the roller 51'. Then while the stock is stationary during the shearing operation, the arm 54' is rotated in a clockwise direction to press the stock down against a stop block 57' to straighten an additional portion of the stock. Subsequently, the arm is returned to its free position, and a subsequent portion of stock is pulled by the machine feed rolls into the straightener. This type of straightener does not require substantial force to move the stock through the straightener and is the type of straightener illustrated in US. Pat. No. 2,646,102. In this embodiment, the pair of rollers 51 may be powered to feed the stock initially through the straightener and furnace and into the feed rolls of the machine.
An embodiment of a preliminary straightener for coils of stock having a horizontal axis is illustrated in FIGS. 3 and 4. In this embodiment, the illustrated preliminary straightener is substituted for the preliminary straightener illustrated in FIG. 1, and may be used in a system incorporating either a secondary straightener as illustrated in FIG. 1 or a secondary straightener as illustrated in FIG. 2.
Referring to FIGS. 3 and 4, the coil of stock 61 is positioned in a vertical plane with its axis 62 extending horizontally. The stock feeds from the coil 61 through a powered straightener 63, consisting of five rolls in the illustrated embodiment, with the pair of opposed rolls 64 and 66 powered to pull the stock from the coil 61 and push the stock past the straightening rolls 67, as
From the rolls 67, which are all joumalled for rotation about horizontal axes, the stock then moves past three vertically joumalled rolls 68, 69, and 71. These rolls are positioned to rebend the stock and provide the stock with the large radius of curvature required for the loop 13. The stock with such large radius of curvature then passes around the loop 13 in the same manner as illustrated in FIG. 1, to a secondary straightener 14, or 14', where it is finally straightened for passage through the heater 16 to the intermittently driven feed rolls 17 of the forging machine 18. The powered rolls 64 and 66 are again driven by a variable speed power source which is controlled by the sensor 21 to maintain the size of the loop 13 within predetermined limits. Here again, the control of the drive for the powered rolls 64 and 66 is arranged so that the rolls stop when the loop reaches a predetermined maximum size in the event that the forging machine operation is terminated.
The roll 69 is also provided with a source of drive power which is used to move the stock past the rolls 68, 69, and 71 when the end of the coil 61 is reached and moves out from between the principal powered rolls 64 and 66. However, normally the roll 69 is not powered when the stock is in engagement with the powered rolls 64 and 66, since these powered rolls provide sufficient drive to push the stock through the preliminary straightening rolls 67 and the rolls 68, 69, and 71, which rebend the stock to a large radius of curvature.
The embodiment of the preliminary straightener illustrated in FIGS. 3 and 4 has the advantage of providing easier material handling, since a typical fork lift truck can be used to easily position the coils of stock 61. Further, because the preliminary straightening provided by the horizontally joumalled rolls 67 functions at right angles to the action of the vertically joumalled rolls 68, 69, and 71, the system tends to eliminate lateral kinks which may exist in the stock in the supply coil 61.
With a feed system in accordance with this invention, it is possible to utilize coils of stock in a hot forging machine in which the intermittent feed system of the machine is utilized to draw the hot stock through the furnace and to also pull the stock through a final straightener without producing sufficient tensile stress in the hot stock to cause elongation problems or the like.
Although preferred embodiments of this invention are illustrated, it is to be understood that various modifications and rearrangements of parts may be resorted to without departing from the scope of the invention disclosed and claimed herein.
1. A hot forging machine system operable with coiled stock having a first radius of curvature comprising intermittently driven feed means operable to intermittently feed stock into a forging machine, a powered first straightener operable to remove stock from a coil and supply such stock to a loop with a radius substantially larger than said first radius of curvature, a secondary straightener operable to receive stock from said loop and complete the straightening thereof, and a heater operable to heat the stock before it reaches said feed means, said feed means being operable to intermittently pull stock through said secondary straightener and heater, said first straightener being operable continuously at a controlled speed to maintain said loop a substantially constant size.
2. A hot forging machine system as set forth in claim 1, wherein said secondary straightener completes the straightening of said stock before said stock enters said heater.
3. A hot forging machine system as set forth in claim 2, wherein said first straightener includes a sensor to determine the size of said loop and control the speed of operation of said first straightener to maintain the size of said loop within predetermined limits.
4. A hot forging machine as set forth in claim 3 wherein said sensor automatically stops said first straightener when the operation of said feed means is terminated.
5. A hot forging machine as set forth in claim 4 wherein means are provided to remove stock from said heater when the operation of said feed means is interrupted.
6. A hot forging machine as set forth in claim 4 wherein a shear and reverse feed means is provided to cut a length of stock within said heater from the stock supply and remove such length from said heater.
7. A hot forging machine system as set forth in claim 6 wherein said secondary straightener is movable to a position clear of said length of stock.
8. A hot forging machine system as set forth in claim 7 wherein the force required to complete the straightening of stock by said secondary straightener is transmitted along heated stock in said heater.
9. A hot forging machine as set forth in claim 8 wherein separate power means are provided to initially move stock through said secondary straightener and said heater to said feed means and are non-operative after said feed means commence to feed stock.
10. A hot forging machine system as set forth in claim 2, wherein said secondary straightener is powered to provide the force required to complete the straightening of said stock and said feed means operates to intermittently move unstraightened stock into said secondary straightener.
1 l. A hot forging machine system as set forth in claim 2, wherein the force required to complete the straightening of stock by said secondary straightener is transmitted along heated stock in said heater.
12. A hot forging machine system as set forth in claim 1, wherein means are provided to support said coiled stock with the axis thereof in a vertical position.
13. A hot forging machine system as set forth in claim 1, wherein means are provided to support said coil of stock with its axis in a horizontal position, said first straightener including a preliminary powered straightener means operable to substantially completely straighten the stock as it feeds from the coil and a secondary means for bending the stock to provide said radius which is substantially larger than said first radius of curvature and supplying said stock to said loop.
14. A hot forging machine system as set forth in claim 13, wherein said first preliminary straightener operates in a vertical plane-and said secondary means operates in a horizontal plane.
15. In a hot forging machine system operable with coiled stock having a first radius of curvature and including intermittently driven feed means operable to intermittently feed stock into a forging machine, and a heater for heating such stock before it reaches said forging machine, the improvement comprising a powered first straightener operable to remove stock from a coil and supply such stock to a loop with a radius of curvature greater than said first radius of curvature, and a secondary straightener operable to receive stock from said loop and complete the straightening thereof as such stock is removed from said loop by said intermittently driven feed means, said first straightener being operable continuously at a controlled speed maintaining said loop at a substantially constant size.
16. In a hot machine system as set forth in claim 15, wherein said first straightener includes a sensor to determine the size of said loop and control the speed of operation of said first straightener to maintain the size of said loop within predetermined limits.