US3173319A - Programmed cut-off mechanism - Google Patents

Description

March 1955 K. R. KESKA ETAL PROGRAMME!) CUT-OFF MECHANISM 3 Sheets-Sheet 2 Filed March 22, 1962 INVENTORS KENNETH R. KESKA a BY LESLIE J; RICE Oberlmmuhgfllommlly :Li l:

ATTORNEYS March 16, 1965 K. R. KESKA ETAL 3,173,319

PROGRAMMED CUT-OFF MECHANISM Filed March 22, 1962 3 Sheets-Sheet 3 3%; E A\\\\\\\\ k\\\\\\\] f FIG 3 IN V EN TOR.

KENNETH R. KESKA a BY LESLIE J. RICE QWU N QF H ATTORNEYS FIG 5 United States Patent ()ffice 3,173,319 Patented Mar. 16, 1965 3,173,319 PROGRAPMED CUT-EFF MEEIHANlSh i Kenneth R. Keska, Bay Village, and Leslie 3'. Rice, North Olmsted, Ohio, assignors to The Yoder Qornpany, Cleveland, Ohio, a corporation of Ghio Filed Mar. 22, 1962, Ser. No. 181,748 12 Claims. (Cl. 8337) This invention relates generally as indicated to a programmed cut-oil mechanism and more particularly to a flying cut-off mechanism and control system therefor which will produce a constant cut-oi? accuracy no matter what the work velocity happens to be.

In ilying cut-oft mechanism for high speed elongated travelling work, it has been found that cut-oft accuracy changes when the work velocity increases or decreases. in press type cut-offs or flying saws, for example, the mass of the cut-off mechanism is substantial and the force required to accelerate such substantial mass to the speed of the work, of course, varies thus affecting the cut-oil accuracy obtained. Accordingly, variations in the cut-off mechanism acceleration rate causes variations in the cut length of the work pieces.

It is accordingly a principal object of the present invention to provide a cut-off mechanism and control which will neutralize the adverse affects of die acceleration rate variation obtaining constant cut-off accuracy regardless of the work velocity.

A further principal object is the provision of a cut-off mechanism having a mechanical control mechanism completely indepedent of the cut-off drive mechanism.

A further object is the provision of such cut-oil mechanism wherein the only variable dependent upon work velocity is the control mechanism intertia which can be kept to a minimum mass by selection of materials and design.

Another object is the provision of such cut-off mechanism which will have a reduced cycle time thus enabling higher speed operation.

Yet another object is the provision such a cut-off mechanism of a highly simplified character.

A still further object is the provision of a cut-oil mechanism having a control mechanism and a drive mechanism which are completely independent of each other so that the inertia and acceleration of each mechanism are isolated completely from each other.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

FIG. 1 is a fragmentary side elevation partially broken away and in section of a press-type cut-off mechanism in accordance with the present invention;

FIG. 2 is a fragmentary top plan view of such presstype cut-off with the press head partially broken away;

IG. 3 is an enlarged detail sectional view taken substantially on the line 3-3 of PEG. 2;

FIG. 4 is an enlarged detail sectional view taken substantially on the line 44 of FIG. 1; and

FlG. S is an enlarged vertical section taken substantially on the line 55 of FIG. 2.

Referring now to the annexed drawings and more particularly to FIGS. 1 and 2, it will be seen that the present invention is illustrated in the embodiment of a conventional press-type cut-elf. It will, of course, be understood that the present invention is equally well applicable to other types of flying cut-oil mechanisms including flying saws.

Such press assembly comprises a base 1 and a head 2 supporting for relative vertical movement the various parts of the cut-oh" die 3. Such die may comprise a circular aperture accommodating an elongated work piece such as a tube and a pointed knife or shear member mounted for vertical movement with the head 2. The die is mounted on the base and head for horizontal reciprocation on pairs of spaced rails, such die being confined to such rails by gibs in a conventional manner. The head 2 is thus provided with a pair of rails 5 and the base is provided with a pair of rails 6 along which the die slides. As seen in FIGS. 1 and 2, the head is mounted on four head rods 8, 9, it) and 11 which extend vertically into the base 1 through upstanding head rod guides 12, 13, 14 and 15, respectively, fixed thereto. As seen more clearly in FIG. 1, the head rod guides are provided with vertically spaced bushings as indicated at 16 and 17 so that the head rods are freely vertically movable within such head rod guides whereby the head will be vertically movable with respect to the base 1. The head 2 is mounted on shoulders of such head rods as indicated at 18 with the top of the rods being threaded and provided with lock nuts shown at 1) with spacers 26 extending between such nuts and the head 2.

The press head will be vertically driven in the conventional manner by a single revolution crank shaft connected by means of a clutch to the main drive motor, such clutch being engaged to cause the blade to be reciprocated downwardly to sever the elongated work piece passing through the die. Reference may be had, for example, to US. Patent No. 2,630,177 and the copending application of Charles J. Bognar, Serial No. 106,857, filed May 1, 1961 for Tube Cut-OE Mechanism for more complete disclosures of press-type cut-off mechanisms.

In accordance with the present invention, the die assembly 3 is connected to the rod 22 of a die assembly shuttle piston-cylinder assembly 23 which is mounted on a base 24 supported on a shelf or bracket 25 secured to the end wall of the base 1 as indicated at 26. The relatively massive die assembly 3 which is confined for movement along the rails 5 and 6 is connected to the rod of the shuttle piston-cylinder assembly 23 to be moved in the direction of the arrow 27 which is the same direction of the travelling work passing through the cut-off mechanism. The die assembly 3 is not physically connected to any other source of motive power.

As seen perhaps more clearly in FIGS. 4 and 5, the lower rails 6 are specially constructed to accommodate a rack slide 30. The rail caps 31 and 32 on which the die assembly 3 is supported project outwardly to overlie the gibs 33 and 34 secured to the bottom of the die assembly. Such rail caps also project inwardly from the tops of the rails 6 to provide channel-shape guideways for the side edges of the rack slide 30. Sets of wear plates 35 and 36 may be employed confining such side edges. Such Wear plates may be bronze and beveled at both ends at an angle of approximately 30. As indicated in FIG. 1, there may be two such sets of wear plates longitudinally spaced along the rack slide properly supporting the rack slide in the inwardly directed channel guides provided by the rails 6 and the respective rail caps. The rack slide 30 is provided at its leading end with a rack stop 38 projecting upwardly between the rails 6 adapted physically to contact the base 39 of the die assembly 3.

A rack 49 is secured to the underside of the rack slide in mesh with a pinion 41 mounted on shaft 42. Such pinion shaft is mounted in pillow blocks 43 and 44 which are in turn mounted on a shelf bracket 45 secured to the end wall of the base 1 of the cut-off press as indicated at 46. The pinion drive shaft 42 has one end connected to a magnetic friction clutch indicated generally at 47 which may be electrically energizable. Such clutch may be, for example, an EATON magnetic friction clutch which, when energized, will drivingly connect shaft 48 to pinion drive shaft 42. Such shaft 48 is mounted in pillow blocks 49 and 50 supported on extension 51 of the shelf bracket 45. The end of the shaft 48 opposite the clutch 47 may have keyed thereto a sprocket 52. The sprocket 52 may be connected by means of a chain drive or the like directly to the mill so that the shaft 48 will always be revolving at a speed synchronized with that of the mill and thus with the speed of the work.

Mounted between the rail caps 31 and 32 as seen in FIG. is a mounting plate 55 for a piston-cylinder assembly 56. Such mounting plate is provided with pairs of inverted T-slots indicated at 57 and 58 accommodating nut and bolt assemblies 59 and 60, respectively. An end plate 62 is secured to the ends of the rails 6 and an adjusting screw 63 is provided properly to adjust the pistoncylinder assembly 56 along the T-slots 5'7 and 58 when the nut and bolt assemblies 59 and 60 are loosened. The rod 64 of the piston-cylinder assembly 56 is provided with a cap 65 adapted to engage the shoulder 66 on the rack stop 38 when the rod 64 is extended.

It can now be seen that the rack slide 30 and the stop 38 thereon, which only touches the base 39 of the die slide assembly and is otherwise not connected thereto, constitutes the control mechanism governing the extent of acceleration of the die slide assembly 3. Thus when the clutch 47 is energized, the rack slide 30 will be driven through the pinion 41 to the left as viewed in FIG. 1 at the same speed and, of course, in the same direction as the travelling work. The rack and rack slide will preferably be made of a light weight material such as aluminum so that the accuracy of the travel of the rack and slide will remain substantially constant regardless of the velocity imparted thereto by energization of the clutch 47 connecting such rack and slide directly with the work drive. Thus if the work is being driven at a relatively higher rate of speed, the rack inertia required to be overcome to impart the proper velocity to the rack and slide will be relatively small.

Operation With the die assembly 3 in its full line starting position indicated in FIGS. 1 and 2; the rack and rack slide extended thereagainst; both the piston- cylinder assemblies 23 and 56 retracted; and the clutch 47 disengaged, the components of the present invention will be at their at rest position.

At a signal from a counter or a limit switch shown schematically at 69 reading the position of the end of the travelling work, the clutch 47 is energized or engaged to cause the rack slide 30 to move to the left in FIGS. 1 and 2 in the direction of work travel and at the same speed as the work. From this same signal, solenoid valve 70 shown diagrammatically in FIG. 2 is energized to put air into the blind end of piston-cylinder 23 to accelerate the die assembly 3. The area of the piston-cylinder assembly 23 and the pressures employed will be such as to tend to accelerate the die assembly 3 to a speed slightly in excess of the speed of the work or the speed of the rack and slide 30. In this manner, the die assembly will overtake and contact the rack stop 38 and the piston-cylinder assembly will then maintain the die assembly against the rack stop travelling at the speed of the work. When the die assembly is in contact with the rack and moving with it at the speed of the work, the die may then trip limit switch 71 (see FIG. 2), which causes the press cut-off cycle to commence closing the press and severing the work. The extent of movement of which the die assembly is capable is shown by the schematic dotted line position of such at 72 in FIGS. 1 and 2.

From a rotary cam limit switch on the press crank shaft, after the cut has been made and the die is open, the clutch 47 will be deenergized or disengaged. Also, the solenoid valve 79 will be reversed to return the die assembly to its original or starting position. This same limit switch may also energize the piston-cylinder assembly 56 to extend the rod 64 to engage the rack stop to return rapidly the die and rack to their original positions. After the piston-cylinder assembly 56 retracts, the system is again at rest ready to start a new cycle of operation. It will, of course, be understood that suitable latches may be employed to hold the die assembly in its start or at rest position with such latches being unlatched at the initiation of the cycle. Since the air applied to the rod end of the piston-cylinder assembly 23 will be acting on less area, it can readily be seen that the return piston-cylinder assembly 56 will more quickly replace the rack and die assembly in their original or at rest positions. It will also be understood that with larger presses, more than one rack may be employed.

It can now be seen that the die acceleration afforded by the piston-cylinder assembly 23 is completely independent of the work position or the work speed. Since the minimum mass of the rack, pinion and clutch will be accelerated in timed relation with the movement of the work, the rack will move away from the end of the die assembly initially only to be contacted again by such die assembly as the piston-cylinder assembly brings the die up to work speed. Since the piston-cylinder assembly will be such as to move the die assembly faster than the work, it will be held firmly against a stop 38 to travel at a governed speed of the work. it is noted that the cycle time of the cut-off varies depending upon the speed of the work with a smaller time elapsing for slower work speeds.

It can now be seen that there is provided a programmed cut-off mechanism which will provide accurate lengths of cut regardless of variations in the work speed.

Other modes of applying the principle of the invention may be employed, change being made as regards the de tails described, provided the features stated in any of the following claims or the equivalent of such be employed.

We, therefore, particularly point out and distinctly claim as our invention:

1. In a flying cut-off mechanism for elongated travelling work, shear means, yieldable drive means for said shear means operative to accelerate said shear means in the direction of travel of such work, stop means, drive means for said stop means operative to move said stop means in the direction of travel of such work at the same speed as such work ahead of and in the same path as said shear means and means operative to energize both said drive means in timed relation, said shear means travelling faster than and overtaking said stop means and being held thereagainst by its drive means to travel with said stop means at the speed of the work.

2. A flying cut-off mechanism as set forth in claim 1 wherein said drive means for said shear means comprises a pneumatic piston-cylinder assembly, and said drive means for said stop means comprises a clutch connecting said stop means to a drive for such elongated travelling work.

3. A flying cut-otf mechanism as set forth in claim 1 wherein said shear means is mounted on a pair of rails for such acceleration in the direction of travel of such work, said stop means being mounted between said rails and comprising a pinion driven rack, said pinion being selectively drivingly engageable with a drive for such travelling work,

4. In a cut-off mechanism for elongated travelling work, cut-off means, yieldable drive means for said cut-off means adapted to accelerate said cut-oft means in the direction of travel of such work to a speed faster than the speed of such work, stop means ahead of said cut-otf means, drive means for said stop means operative to move said stop 3 means in the direction of travel of such work at the same speed as such work and in the same path as said cut-off means, means operative simultaneously to energize said drive means, said cut-E means thus overtaking said stop means to be held thereagainst travelling at the speed of the work.

A cut-01f mechanism as set forth in claim 4 wherein said cut-off means has a substantially greater inertia than said stop means, said stop means being made of lightweight metals adapted to reduce the inertia thereof,

6. A cut-off mechanism as set forth in claim 5 including rail means mounting said cut-off means for such acceleration in the direction of travel of such work, said stop means being mounted for such movement in said rail means and having a stop block thereon adapted to engage said cut-off means.

7. A cut-01f mechanism as set forth in claim 6 wherein said rail means comprises a pair of spaced rails extending in the direction of travel of such work, and rail caps on said rails projecting inwardly and confining said stop means for such movement.

8. A cut-off mechanism as set forth in claim 7 including a return piston-cylinder assembly, the rod of which is adapted to engage said stop block and return said stop means to its original position.

9. A cut-01f mechanism as set forth in claim 8 wherein 6 said stop block projects upwardly between said cut-off means and said rod to be engaged by both.

10. A cut-01f mechanism as set forth in claim 9 wherein said drive means for said cut-0E means comprises a pistoncylinder assembly, the rod of which extends in the opposite direction as the rod of said return piston-cylinder assembly.

11. A cut-ofi mechanism as set forth in claim 10 including an electromagnetic clutch operable to disengage said drive means for said stop means prior to the extension of the rod of said return piston-cylinder assembly.

12. In a flying cut-off mechanism for travelling work the method of controlling the speed of such flying cut-0H1 mechanism, comprising the steps of simultaneously accelerating such cut-01f mechanism to a speed in excess of such travelling work while moving a stop ahead of such cut-off mechanism at the speed of the work, thereby to cause such cut-off mechanism to contact such stop and be held thereby to the speed of such work, and thereafter severing such Work,

References Cited in the file of this patent UNITED STATES PATENTS 1,911,150 Hallden May 23, 1933 2,271,145 McKinney Ian. 27, 1942 2,540,166 Frank Feb. 6, 1951

Claims (1)

1. IN A FLYING CUT-OFF MECHANISM FOR ELONGATED TRAVELLING WORK, SHEAR MEANS, YIELDABLE DRIVE MEANS FOR SAID SHEAR MEANS OPERATIVE TO ACCLERATE SAID SHEAR MEANS IN THE DIRECTION OF TRAVEL OF SUCH WORK, STOP MEANS, DRIVE MEANS FOR SAID STOP MEANS OPERATIVE TO MOVE SAID STOP MEANS IN THE DIRECTION OF TRAVEL OF SUCH WORK AT THE SAME SPEED AS SUCH WORK AHEAD OF AND IN THE SAME PATH AS

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