The present invention relates to combination punch press and laser cutting machines and more particularly to an improved assembly for mounting the laser beam generator on the punch press frame and for delivering the laser beam to the nozzle of the cutting head located on the axis of reciprocation of the ram.

Combination punch press and thermal cutting machines have enjoyed substantial acceptance in providing a high degree of versatility in sheet metal processing since the user may readily punch or nibble small holes and thermally cut larger ones on the container of the finished workpiece. Although plasma cutting had been favored for cost and speed considerations, particularly in some industrial environments, development of improved, relatively low cost high powered lasers has led to wider usage of laser cutting.

Clark et al U. S. Patent No. Re. 31,042 discloses that it is necessary to space the laser beam generator from the punch press machine in order to isolate it from the punch press vibrations, and also to provide a second work station for the laser cutting operation which is offset from the punching station. Klingel U. S. Patent No. 4,698,480 discloses the advantages to, and an apparatus for, placing the laser beam cutting head at the punching station so that there is a single work station about which the workpiece is moved and suggesting supporting the laser beam generator on the punch press frame. Recently, Amada German Offenlegungsschrift No. De 3814630 Al has proposed mounting the laser beam generator on an extension

of the base of the punch press machine frame and transporting the laser beam over the head of the frame and then downwardly to the cutting head at a work station offset from the punching station.

Mounting the laser generator on or adjacent the punch press frame does present a problem from the standpoint of minimizing the possible deleterious effect of vibrations on the laser generator. It has been known to use fluid vibration absorbing or damping means under the punch press to minimize the transmission of vibrations to the underlying support for the machine base and then to other equipment in the surrounding environment. The aforementioned Amada Offenlegungsschrift utilizes such fluid absorbing damping means between the machine frame and the laser beam generator. However, both the base and the head of the frame are subject to appreciable vibrations since the base receives the impact of the punching action, and the head reacts to the impact forces delivered to the base by the ram. In C-shaped frames, the head is an elongated element supported only at its rearward end and the punching action is at its forward end so that it may oscillate during the punching operation.

It is also generally considered desirable to produce angular and planar redirection of the laser beam along its path from the generator to the cutting head to avoid polarization of the beam. Moreover, it is desirable to locate the laser beam generator and can transport systems at readily accessible and observable locations.

It is an object of the present invention to provide a novel combination punch press and laser cutting machine in which the laser beam generator is carried on a generally C-shaped punch frame at a location of relative stability and at which the generator is readily accessible and observable.

It is also an object of the invention to provide such a novel combination machine in which the laser beam is transported along the frame to the cutting head in a path which is readily accessible for observation and servicing and which also effects redirection of the beam to avoid its polarization.

Another object is to provide such a machine in which the laser cutting head is readily moved from an inoperative position offset from the punching station to an operative position in which its nozzle is coaxial therewith.

Still another object is to provide such a machine in which various operations are performed rapidly and accurately under computer control.

SUMMARY OF THE INVENTION

It has now been found that the foregoing and related objects may be readily attained in a combination punch press and laser cutting machine comprising a substantially rigid frame of generally C-shaped configuration with an elongated base, an elongated head extending in spaced relationship thereabove, and a vertically extending neck therebetween at the rearward end of the frame. The neck defines the vertical height of an open throat between the head and base, and the frame has a platform extending rearwardly from the neck and providing a horizontal surface at the neck.

A ram assembly is mounted in the head adjacent its forward end for reciprocation of a ram relative to the base to punch workpieces disposed on the base. Mounted on the forward end of the head is a laser cutting assembly including a cutting head having a nozzle at its lower end, a lens for focusing the laser beam and a mirror spaced above the nozzle for directing the laser beam into the nozzle.

A laser beam generator is mounted on the platform and has an exit aperture adjacent one side of the neck, and vibration isolating means is disposed between the platform and the laser beam generator. A laser beam transport assembly includes an elongated enclosure extending forwardly from the laser beam generator exit aperture along the side of the frame to the forward end of the head. Included at the forward end thereof is a beam redirection assembly having a series of mirrors effecting a redirection of the laser beam, in both vertical and horizontal directions and in two different planes, to a mirror in the cutting head.

In the preferred embodiment, the platform includes a rigid horizontal member on the neck providing the surface on which is disposed the laεer generator, and braces extending downwardly therefrom and secured to the frame. These braces are at least predominantly secured to the neck and base of the frame. The isolating means includes means for lifting the generator above the platform and providing an isolating fluid support for the generator during punching operations. Desirably, the isolating means additionally includes positioning elements which guide and locate the generator in

precise horizontal and vertical position on the platform upon inactivation of the lifting means. The transport assembly includes a flexible coupling between its rearward end and the exit aperture of the generator.

Preferably, the laser cutting head is supported on the head of the frame for movement between a position locating the nozzle coaxial with the axis of reciprocation of the ram and a position offset therefrom. Mounting and movement means mount the cutting head on the head of the frame and provide the movement thereof between the two positions. Such means provides rotation of the head about a vertical axis thereof offset from the axis of reciprocation of the ram and movement along a vertical axis when in its position rotated from the ram axis. The mounting and movement means also effects movement of the nozzle along a horizontal axis relative to the ram axis of reciprocation.

Preferably, the ram assembly includes a punch mounting portion and a position of the cutting head has a locating element thereon which seats in the punch mounting portion to locate the nozzle in precise coaxial alignment with the ram axiε of reciprocation.

In its most desirable form, the machine includes tool mounting means on the ram asεembly and in the baεe, tool carrier meanε carrying a multiplicity of puncheε and cooperating dieε for mounting in the tool mounting meanε, and tool changer means for movement of the punches and dies between the tool carrier means and tool mounting means. The beam redirection system has a mirror directing the laser beam

upwardly and forwardly of the axis of ram reciprocation, and a second mirror directing the beam downwardly along a vertical axis parallel to the axis of ram reciprocation. The laser cutting head has a horizontally extending lower portion having the nozzle depending therefrom at its one end, a mirror disposed thereabove to direct the horizontally extending laser beam downwardly into the nozzle, and a mirror spaced towards its other end to redirect the downwardly extending laεer beam horizontally to the first mentioned mirror. The horizontally extending lower portion is movable along a horizontal axis into alignment with the axis of reciprocation of the ram. There is connected to the horizontally extending portion at least one conduit for gas to be discharged through the nozzle and there is also connected to the horizontally extending portion a conduit for a fluid to cool the optics therein. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a fragmentary side elevational view of a combination punch presε and laser cutting machine embodying the present invention εhowing the laεer cutting head in operational position;

Figure 2 iε a top plan view thereof with a portion of the worktable broken away and additionally showing additional elements of the installation;

Figure 3 is a fragmentary side elevational view of the rear end thereof drawn to an enlarged scale and with various elements in partial section;

Figure 4 is a schematic view εhowing the path of the laεer beam from the laser beam generator to the nozzle of the cutting head;

Figure 5 is a semi-diagrammatic view of the laser cutting head at its operative position and showing the laser beam cutting a workpiece;

Figure 6 is an enlarged elevational view of the front end of the frame with the cutting head removed and showing the mounting and moving means for the laser cutting head assembly in operative position and the forward end of the beam tranεport εyεtem;

Figure 7 iε enlarged εide elevational view of the elementε of Figure 6 and the cutting head, with a portion of the head of the frame and ram shown in phantom line and with the cutting head in operative position;

Figure 8 is sectional view of the cutting head asεembly as seen from the opposite side of the frame;

Figure 9 is a fragmentary semi-diagrammatic view of the front of the machine showing the cutting head in its inoperative position;

Figure 10 is a similar view showing the cutting head moved downwardly in a first step in is movement to operative position;

Figure 11 is a similar view showing a portion of the cutting head rotated about its vertical axis in a εecond εtep in itε movement; and

Figure 12 iε a similar view in partial section showing a portion of the cutting head extended to locate the nozzle of the cutting head and asεociated opticε in operative poεition.

DETAILED DESCRIPTOIN OF PREFERRED EMBODIMENT OF THE INVENTION

Turning firεt to Figureε 1 and 2, therein illuεtrated is a combination punch presε and laεer cutting machine embodying the preεent invention. The machine haε a rigid frame generally designated by the numeral 10 which is of generally C-shaped configuration with an elongated base 12, an elongated head 14 extending thereover in vertically spaced relationship, and a spacing web or neck 16 extending therebetween at the rearward end 'thereof. The web 16 defines the height of the throat 18 or spacing between the head 14 and base 12, and it also limits rearward movement of the workpiece and support and guidance systemε for the workpiece (i.e., the length of the throat) .

Carried on the base 12 is a worktable 20 which supportε the workpiece 22, and a ram assembly generally designated by the numeral 24 is diεposed at the forward end of the head 14. The axis of reciprocation is of the ram 25 is designated by the dotted line 26 and it defines the work station for the machine. The workpiece clamping and guidance syεtem 28 iε εupported on the base 12 and moves the worktable 20 in one direction and moves the workpiece 22 about the worktable 20.

Also mounted in the base 12 is a tool storage and changer syεtem generally deεignated by the numeral 30 and of the type illustrated in Klingel U.S. Patent No. 4,719,691. It has a circular storage member 32 rotatable about a horizontal axis, and it seatε a number of punch and die εetε (not εhown) in recesεeε about its circumferences. It is movable rearwardly by the drive unit 34 to εeat, or to engage and remove, puncheε

and dies, in the tool mounting portion 32 at the base of the ram asεembly 24 and die support member (not shown) in the base 12.

Also seen in Figure 2 is a control console 40 for the computer control unit 42 and a hydraulic unit 44 which provides hydraulic fluid under pressure to reciprocate the ram 25, and to effect operation of various other elements under the control of the control unit42. Also shown in a pneumatic unit 45 which supplies air under presεure to variouε other elementε of the machine deεcribed hereinafter and it iε also under control of the control unit 42.

As seen in Figure 1, the frame 10 has a platform aεεembly generally designated by the numeral 48 which extends rearwardly thereof at its web portion 16. The platform asεembly 48 includeε a horizontal member 50 and εtruts or braces 52 which are diεpoεed therebelow and extend to the web portion 16 and baεe 12. Seated on the horizontal member 50 iε a laεer beam generator generally deεignated by the numeral 54 and having an exit aperture 56 disposed to one side of the frame 10. The power to ionize a lasing gas in the generator 54 is provided by the high frequency generator 58, and the control unit therefor is designated by the numeral 60 and is alεo coupled to the computer control unit 42 and the conεole 40.

Mounted on the forward end of the head 14 of the ::rame 10 iε a laεer cutting head generally deεignated by the numeral 62. Extending from the exit aperture 56 of the laεer generator 54 to the cutting head 62 iε a beam transport

aεεembly generally deεignated by the numeral 64 and including a flexible bellowε portion 66 at itε rearward end providing the terminal portion to the aperture 56. At its forward end is a beam redirecting system generally designated by the numeral 68 and operatively coupled to the cutting head 62.

Turning now to Figure 3, therein illustrated are vibration iεolating memberε 70 εupporting the laεer beam generator 54 on the horizontal element 50 of the platform 48. In the punching mode, air under preεεure iε supplied through the conduit 71 to the cylinders of the members 70 to move the pistons upwardly, and the generator 54 is thus supported on a fluid medium which damps vibrations. This operation is effected by controlling valves (not shown) to supply air from the pneumatic unit 45 by action of the control unit 42 when the machine is to perform in the punching mode. Also shown are cooperating elements 72, 74 on the base of the laser beam generator 54 and platform element 50 to precisely position the laser beam generator 54 in its lowered and operative position. Upon withdrawal of the fluid from the members 70, the generator 54 descendε and iε poεitioned by the elementε 72, 74. Aε seen in Figure 3, the flexible portion 66 of the beam transport assembly 64 flexes to accommodate the vertical displacement of the laser beam generator 54.

As indicated in Figures 1-5, the laser beam 76 pasεeε through the tube 78 of the baεe tranεport aεεembly 64 to the front of the head 14 of the frame 10, and it iε diεposed to one side of the machine frame 10 and along its throat 18. At the forward end, it has a beam redirecting component 68 with

an angularly disposed mirror 80 which has a coating thereon with a thickness equal to one fourth the wave length of the beam to change the linear polarization of the beam into a circular polarization. The mirror 80 redirects the beam at an angle of about 45 upwardly and inwardly to a mirror 82 which is located on the centerline of the head 14. This mirror 82 is angular dispoεed and redirects the beam at an angle of 45° downwardly to the mirror 84 in the cutting head 62. Spaced from the mirror 84 is a lens 86 which partially focuses the beam onto the surface of the mirror 88 which further focuses the beam and redirects it at an angle of 90° through the aperture in the nozzle 90 onto the workpiece 22.

Below the workpiece 22 in the base 12 iε a cooperating fixture 92 which has water flowing therein to cool it and carry slag away, and it is also connected a source of suction to draw away fumeε generated by the thermal cutting proceεs.

The laser cutting head 62 is seen in greater detail in Figures 6-12. Brackets 100 are mounted on the front face of the head 14 of the frame 10, and mounted upon them are the εupport barε 102 which εlidably εupport the support frame 104 of the laser cutting head 62 (not shown in Figure 6). Movement of the laser cuttinσ head 62 vertically up and down is effected by action of t piston 106 in the pneumatic cylinder 108. As best seen in Figure 8, the cutting head 62 has a telescoping vertical tubular conduit provided by a fixed section 110 and a sliding section 112 to provide an extensible enclosed vertical cloεed paεεage for the laser beam from the mirror 68 at the end of the beam transport assembly 68.

At its base, the cutting head 62 has a horizontally dispoεed teleεcoping tubular conduit provided by a fixed εection 114 and the εection 116 which iε movable by the air actuated motor 118. On the upper surface of the movable section 116 is an upstanding boss 120 which seats in the punch mounting recess 36 at the base of the ram 25.

To dampen the effect of vibrations of the punch presε upon the opticε, the bracketε 101 mounting the cutting head aεεembly are diεpoεed on εpringε 124 diεpoεed about the guide bolts 125 as seen in Figure 6.

The cutting head 62 is also rotatable about a vertical axis by the belt drive 127 on the motor 126.

Motion of the laser cutting head 62 is partially schematically illustrated in Figures 9-12. In Figure 9, the cutting head 62 is dispoεed in itε elevated, rotated and inoperative poεition.

Upon command from the computer control 42, the air cylinder 108 iε actuated to move the cutting head 62 downwardly to the poεition seen in Figure 10 at which time the cutting nozzle 90 is disposed in the horizontal plane required for its intended operation.

The motor 126 for the drive belts 27 iε then actuated to rotate the cutting head 62 about the vertical axiε aε εeen by the arrow in Figue 11, and thiε pivots the nozzle 90 to a position closely adjacent the baεe of the ram 25. The air motor 118 iε then actuated to move the teleεcoping εection 116 to the right aε seen in Figures 11 and 12 which causes the boss 120 to fit into the punch mounting recesε 36 at the baεe

of the ram 25, thuε, bringing the nozzle 90 into coaxial alignment with the axiε of ram reciprocation. Simultaneously, the mirror 84 is the telescoping tube 112 is moved into alignment with the mirror 82 in the beam redirection syεtem 68 aε εhown in Figure 12.

Thus, then the laser beam generator 54 is rendered operational and the laser beam 76 exits therefrom, it pasεeε through the laεer beam transport asεembly 64 to the mirror 82 and then downwardly through the telescoping tubes 110, 12 to the mirror 84. It is then directed towards the focusing lens 86 and mirror 88 which focuε the beam 76 through the aperture in the nozzle 90 and onto the workpiece 22.

By locating the laεer beam generator on a platform at the central web or neck of the punch preεε frame, the laεer beam generator is positioned at a stable portion of the frame. Unlike the head, this area is free from bending moments produced by the ram action, and the vibrations in the head and the base are materially dampened by the time that they pass into this section of the frame. Moreover, the mounting of the laser beam generator at this location permitε facile εervicing and observation of its operating components. It also enables tranεport of the laser beam along the side of the punch presε through a transport asεembly which iε readily inεpected and εerviced.

By this arrangement, it iε also easy to redirect the laser beam through a change in angles and planes to avoid its polarization, while minimizing the number of mirrors which must be utilized to do so. As will be readily appreciated,

the mirrors in such transport assemblies in this environment are subject to damage and require precise adjustment.

By providing the mounting of the laser cutting head in a manner which permits its movement from an operative position for the laser nozzle to an inoperative position removed from the working area of the ram, the machine operator is able to observe the punching operation, and there is lesε likelihood of injury to elements of the laser cutting head during the punching operation.

As will be appreciated, the computer control for the machine effects the operation of the various motors and cylinders to perform the various steps required to bring components into operative position, and to perform the punching or laser cutting operations. The control console is equipped with the typical safety devices for laser operation.

As will be appreciated, the illustrated construction is one which is readily adapted to punch preεses having automatic tool changers for exchanging the tools in the punch ram and in a die support located in the base. Because the laser cutting head can be moved to an inoperative position, it will not effect the typical movement of the tools from a position forwardly of the ram into the tool mounting portions.

Thus, it can be seen from the foregoing detailed specification and attached drawings that the machine of the present invention carries the laser beam generator on the punch presε at a location of relative εtability where it is readily acceεεible and obεervable, and it tranεportε the laεer beam therefrom to the cutting head in a path which iε alεo

readily accessible for operation and servicing, while at the same time providing simple and economical means for effecting redirection of the beam to avoid polarization. The laser cutting head is readily moved from an inoperative position offset from the punching station to an operative position in which its nozzle is coaxial therewith so as to require only one work station. Moreover, the various operations may be performed automatically and accurately under computer control.