The present invention relates to a flying cut-off mechanism mountable on slide rods and having an accurate length control mechanism associated therewith. The accurate length control mechanism includes a shock absorber against which a continuously moving elongate stock or work piece abuts before being cut by a die cutter which moves with the workpiece.

The shock absorber not only absorbs the initial force of impact from a moving work piece, but also provides a method of imparting a uniform and controlled acceleration of a carriage assembly carrying the die cutter and the shock absorber.

This uniform acceleration is ensured by the constant resistive force of gravity that is applied by a weight acting on the carriage through a series of pulleys.

2. Description of the Prior Art.

Heretofore a variety of flying cut-off machines have been proposed, and examples of several previously proposed flying cut-off machines or mechanisms are disclosed in the following U. S. patents: U. S. Patent No. Patentee 4,228,706 Borzym 4,727,783 John, Jr.

4,852,440 Bald 5,125,250 Sun 5,690,011 Hill, et al.

SUMMARY OF THE INVENTION According to the present invention there is provided a flying cut-off mechanism including an accurate cut work piece length control system and comprising: a carriage including a cutting assembly comprising a cutter and a cutter operating mechanism and a work piece stop and work piece ejecting mechanism both of which are constructed and arranged for being slidably mounted on at least two slide rods, and an adjustably positionable rod connected between the cutting assembly and the stop and ejecting mechanism for holding them a predetermined distance apart on the slide rods. The cutting assembly has a lateral or transverse passageway extending therethrough for receiving an elongate moving work piece. The stop and ejecting mechanism includes a shock absorbing device constructed and arranged to be engaged by an outer free end of the moving workpiece and compressed a predetermined distance. The carriage is moved by the work piece until the cutter operating mechanism is actuated for cutting a precise length of work piece situated between the cutter in the cutting assembly and the compressed position of the shock absorbing mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS The single Figure of the drawings is a partially schematic, block, front plan view of the flying cut-off mechanism constructed according to the teachings of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT (S) As illustrated in the Figure, the flying cut-off mechanism with accurate length control for cut work pieces of the present invention is generally identified by the reference numeral 10 in the Figure.

This mechanism 10 includes at least two, fixed in place, slide rods, a lower, forward rod 12 and an upper, rear rod 14 on which the mechanism 10 is mounted for sliding movement, right-to-left and then left-to-right.

The flying cut-off mechanism 10 is schematically illustrated in the Figure and includes a carriage 15 comprising, as basic components thereof, (a) a cutting assembly 16 which is slidably mounted on the two slide rods 12 and 14, (b) a work piece stop and work piece ejecting mechanism, or simply, stop and ejecting mechanism 18, positioned to the right of the cutting assembly 18 and also mounted on the two slide rods 12 and 14, and (c) a threaded rod 20 which is fixed to the cutting assembly 16 and to the stop and ejecting mechanism 18 to hold them relative to each other thereby to form the carriage 15.

As shown, the cutting assembly 16 is typically a"Pneumatic Toggle Press"sold by BTM corporation of Marysville, Michigan and includes a block shaped housing 22 which is made of plates that are bolted together (the bolts not being shown here for convenience) and which has therein a bore extending laterally therethrough for receiving one end of the threaded rod 20. Then, the threaded rod 20 is secured to the housing 22 by threaded nuts 26 and 28.

Also mounted in the housing 22 are two journal bearings 32 and 34 which slidably receive therethrough, respectively, the slide rods 12 and 14. Again, it is to be understood that the cut-off mechanism 16 is movable on the slide rods 12 and 14.

As shown, right hand ends 42 and 44 of the slide rods 12 and 14 are fixed in a C-in- cross-section beam 46 which is mounted on an upright frame member 47 supported on a stationary support or floor 48. At the top 50 of the frame member 47 is mounted a stub shaft 52 on which is mounted a pulley or idler roller 54.

As shown, one end 56 of a cable or rope 58 is fixed to a right hand side of the housing 22 and then extends around the pulley or idler roller 54 and to the left to an idler roller 60 mounted to the far left of the flying cut-off mechanism 10 and pivotably mounted on an upright frame member 62 mounted on the fixed support or floor 48.

An outer end 64 of the cable or rope 58 is connected to a weight 66 so that there is a constant weight pulling on the housing 22 to pull the housing 22 to the right.

Extending through the housing 22 is a through passage 68 through which an elongate rod-like stock or work piece 70 is continuously moving from right to left, as shown by the arrow 72.

If desired, an inclined surface 74 can be provided at the entrance to the passageway 68 so that in the event of gravity droop of the work piece 70, after it is cut, it will engage the curved surface 74 and be aligned again to move horizontally to the left in line with the work piece stop and cut work ejecting mechanism 18. This usually does not happen, since the workpiece 70 is continuously moving to the left, even after it is cut. Also, at the same time, after the workpiece 70 is cut, the weight 66 pulls the carriage to the right until the workpiece 70 hits the stop and ejecting mechanism 18.

Also, as shown in the Figure, an upper side 76 of the passageway 68 is significantly above the workpiece 70 to allow for movement of the cut end of a cut work piece 78 upwardly after the cut work piece 78 is ejected from the mechanism 10 by the stop and ejecting mechanism 18.

It will be understood that mounted within the cutting assembly 16 is a cutting blade 80, shown schematically, which is slidably received in a vertical slot and driven by a piston rod 83 extending from a cylinder 84.

As shown, a source of pressurized fluid, pneumatic or hydraulic, is supplied to an upper end of the cylinder 84 via a conduit 86 and then spent pneumatic or hydraulic fluid exits the cylinder 84 via a conduit 88.

As will be described in greater detail hereinafter, the operation of the cylinder 84 is synchronized with the operation of a workpiece ejecting cylinder 90 in the stop and ejecting mechanism 18.

Turning now to the work piece stop and cut work piece ejecting mechanism 18, simply referred to as the stop and ejecting mechanism 18, it will be seen from the Figure that the threaded rod 20 is fixed to an upright elongate fixture 94 of the mechanism 18 by two threaded nuts 96 and 98. The fixture 92 provides a support for a horizontally extending plate 100, a lower bearing journal 102 and an upper bearing journal 104 receiving the slide rod 14. The bearing journal 102 is received on the slide rod 12 for holding the mechanism 18 on the slide rods 12 and 14.

Below the plate 100 and the fixture 92 is a shuttle assembly 110 which includes a support framework 112 which mounts a shock absorber 113 typically of the type sold under the trademark"ENDINE"by Endine, Inc. or Orchard Park, New York, and

typically including a cylinder 114, a piston rod 116, a shock absorbing end plate or stop 118 at an outer end of the piston rod 116 and a spring 120 around the piston rod 116.

It will be understood that hydraulic fluid is provided in the cylinder 114 and the piston rod 116 extends from the cylinder 114 to the end plate or stop 118.

The shuttle assembly 110 including the support framework 112 has two pivot rods 122 and 124 extending therethrough at each end 126 and 128 of the support frame 112. The pivot rod 122 has journaled thereon, an upwardly extending plate or bar 130 which is fixed at its upper end to the plate 100 mounted on the fixture 92.

On the pivot rod 124 is pivotally mounted one end 132 of a piston rod 136 extending from the cylinder 90. The upper end of the cylinder 90 is fixed to a bracket 138 which in turn is fixed to the upwardly extending fixture 94.

If desired, a guide block (not shown) can be mounted in the support framework 112 for guiding a free end 141 of the workpiece 70 into engagement with the end plate or stop 118. Also, a stop surface 142 can be provided at an outer end of the cylinder 114 for being engaged by a back side of the end plate or stop 118 to limit the stroke of movement S of the stop 118.

It will be understood, as known in the art, that the moving stock or work piece 70 typically comes off a roll, such as a roll of extruded aluminum stock, e. g., stock having a C-shaped cross-section that is used for making metal door steps or metal framing members. The moving stock 70 comes off of a large roll (not shown) and typically extends through several pairs of upper and lower guiding, aligning and feeding rollers (not shown) which are positioned to the left of the flying cut-off mechanism 10 between the flying cut-off mechanism 10 and the roll of stock or workpiece 70.

OPERATION In the operation of the flying cut-off mechanism 10, the stock 70 comes into the mechanism 10 at various speeds and can be at a speed of up to 125 feet per minute or more. The work piece 70 moves in the direction 72 through the passageway 68 and into engagement with the end plate or stop 118 where it starts to move the whole assembly 10 and at the same time compresses the spring 120 and/or forces the piston rod 116 into the hydraulic cylinder 114. The shock absorber 114 not only absorbs the initial force of impact from the moving workpiece 70 but also provides a method of imparting a uniform and controlled acceleration of the carriage 15. This

uniform acceleration is ensured by the constant resistive force of gravity that is applied by the weight 66 acting through a series of pulleys 54 and 60. The stroke of movement of the shock absorber end plate or stop 118 is indicated by the letter S and is typically one inch. Accordingly, after the work piece hits the stop end 118 and moves the shock absorber one inch, it is assured that a precise length of work piece 70 is located between the blade 80 and the bottomed out end plate or stop 118. This length L can be between 5 inches and 50 inches, depending on the setting of the length of the threaded rod 20 between the cutting assembly 16 and the stop and ejecting mechanism 18.

It will be understood, that after the bottoming of the end plate or stop 118 with the stop surface 142, the assembly 10, including the housing 22, the threaded rod 20 and the stop and ejecting mechanism 18, is moved to the left for a short distance and for a very short period of time. In this respect, once the stop 142 has been hit, the mechanism 10 knows that a precise length of work piece 70 extends between the front end of the end plate or stop 118 and a lower edge of the cutting blade 80. This length is identified by the reference letter L, the length of the cut work piece 78, and can vary depending upon the dimension required, and typically varies between 5 and 50 inches. In the meantime, the weight 66 which initially pulled the mechanism 10 to the right is moved upwardly as the end 141 of the work piece 70 engages end plate or stop 118 and moves the carriage 15 to the left.

Once the shock absorber stop 118 has been depressed to its limit, namely one inch, the cylinder 84 is activated to cause the cutting blade 80 to move downwardly and cut the work piece 70 with the cutting blade 80 moving downwardly against an anvil surface 147 forming a bottom side of the passage 68. At the same time, or a very short time thereafter, the cylinder 90 is activated to move the piston rod 136 upwardly to move the end of the shuttle assembly 110 downwardly. When this happens, the piston rod 136 is caused to move upwardly by the cylinder 90 to cause the cut section 78 of work piece 70 to come free from the flying cut-off mechanism 10 and fall down into a chute (not shown) and laterally (out of the plane of the Figure) where cut work pieces 78 are collected.

Again, it is to be noted that the length L of the work piece can be adjusted by turning the threaded nuts 96 and 98 to move them on the threaded rod 20 until a desired length L is established.

Further, it will be understood that the mechanism 10 operates continuously

causing the carriage 15 to go back and forth. First, it goes to the right under the pull of the weight 66 and then when the end 141 of the work piece 70 hits the end plate or stop 118 of the shock absorber 113, the carriage 15 moves to the left until the shock absorber 113 is compressed the stroke distance S, typically one inch, at which time the cylinder 84 is activated to cause the cutter blade 80 to cut the work piece 70 followed by activation of the cylinder 90 to move the piston rod 136 upwardly causing the end 126 to rotate clockwise about the rod 122 to cause ejection of a cut work piece 78 away from the flying cut-off mechanism 10.

Then, while the work piece 70 is still moving to the left, the weight 66 pulls the flying cut-off mechanism 10 to the right until the outer end 141 of the work piece 70 again engages the stop 118 of the shock absorber 113. This continues until the machine (not shown) feeding the work piece 70 to the left is shut down or all of the coiled work piece 70 has come off the large roll.

From the foregoing description, it will be appreciated that the flying cut-off mechanism 10 with accurate work piece length control of the present invention described above has a number of advantages, some of which have been described above and others of which are inherent in the invention. Also, it will be apparent that modifications can be made to the flying cut-off mechanism 10 of the present invention without departing from the teachings of the invention. Accordingly, the scope of the invention is only to be limited as necessitated by the accompanying claims.