US3540339A

US3540339A - Stripper-holddown assembly for punch presses

Info

Publication number: US3540339A
Application number: US699225A
Authority: US
Inventors: John S Killaly
Original assignee: JOHN S KILLALY
Current assignee: JOHN S KILLALY
Priority date: 1968-01-19
Filing date: 1968-01-19
Publication date: 1970-11-17
Anticipated expiration: 1987-11-17

Description

United States Patent lnventor 3,140,630 7/1964 Wolf 83/140 7 FOREIGN PATENTS 950,807 2/1964 Great Britain 83/552 Primary Examiner-William S. Lawson Attorney-Paul & Paul ABSTRACT: A combination stripper and holddown is provided, carried by a punch press machine, either of the single station or turret types, as opposed to being carried by a punching ,tool or a tool adaptor. Such a mounting for the stripper and holddown combination permits ease of access to the tool holder and adaptor, for removal or replacement thereof, as for example during a change in tool size. In the single station type of punch press, the stripper and holddown assembly is mounted on a spacer carried by the ram adaptor and a dishlike plate, the plate having a lower planar surface which engages a workpiece for clamping the same, with the stripper cap being threadably connected into the dishlike plate. The turret type of punch press utilizes a platelike stripper and holddown-assembly. carried by and axially movable relative to the rotary turret plate. and vertically driven by a C-shaped yoke or spacer which is spring carried by the ram adaptor.

Patented Nov. 17, 1970 3,540,339

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INVENTOR. John S. Killoiy WPM ATTORNEYS.

Patented Nov. 17, 1970 Sheet ATTORNEYS.

Patented Nov. 17, 1970 3,540,339

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M John S. Killoly BY 8 WwMZw ATTORNEYS.

STRIPPER-HOLDDOWN ASSEMBLY FOR PUNCH PRESSES BACKGROUND OF THE INVENTION Punch presses of the prior art types have used stripper and holddown combinations, but such stripper and holddown combinations or units thus utilized are generally mounted on or carried by either of the punching tools, or tool adaptor, for example as disclosed in my own prior U.S. Pat. No. 3,296,905, granted Jan. 10, 1967.

Devices of this type have proven to be particularly desirable for applying combination stripper-holddown units to existing punch presses, in that the units, particularly those disclosed in said above-mentioned patent are compact and readily assembled onto existing punch adaptors and the like.

While stripping and holddown assemblies of the above-mentioned patented type have been successful for modifying existing punch press machines, certain disadvantages are present in such units, such as the problem of having to remove the stripper-holddown unit assembly whenever it is desirable to change a punch and punch adaptor. Thus, there is a need for providing in the punch press art, a stripper-holddown unit, wherein the stripper is generally of the stripper-plate type, and comprises a part of the holddown unit, and wherein the stripper-holddown unit is carried in such a way as to permit ready accessability and quick-release interchangeability of tools and tool adaptors, without requiring removal of the complete stripper-holddown unit carrier assembly.

SUMMARY OF THE INVENTION The present invention seeks to provide a solution to the problems discussed above, and to obviate the problem of tool and tool adaptor interchangeability and replacement, without interference from the stripper-holddown spacer, in providing a punch press apparatus having a stripper-holddown unit that is capable of quick release and that is, built into the machine itself, and carried thereby, as opposed to being carried, by a tool or tool adaptor, in order to provide ready access for removal and interchangeability of tools and tool adaptors, but yet providing an effective stripper-holddown combination utilizing a stripper of the plate type, the stripper-holddown unit being resiliently carried by the ram or ram adaptor, and being free of any support whatever from either of the tool or tool adaptor and being actuated through a spacer that spans the tool and tool adaptor.

Accordingly, it is a primary object of this invention to provide a punch press, either of the single station or turret types, wherein a combination stripper-holddown spacer unit is mounted as an integral part of the machine, with the spacer and unit being free of attachment to and lateral support from either of the tool or tool adaptor, for facilitating tool removal and replacement.

It is a further object of this invention to provide a punch press of the type set forth immediately above, wherein the combination stripper-holddown unit utilizes planar surface means for clamping a workpiece against a lower die, wherein a stripper cap is provided, either of the self-punching or rotatable toolfollowing type.

It is a further object-of this invention to provide a punch press of the type set forth in the objects above, wherein the press is of the single station type, and wherein the stripperholddown unit is carried by a spring seated plate mounted for axial movement along the ram adaptor, with the unit being a readily removable bottom dishlike member.

It is yet another object of this invention to provide a punch press of the turret type, utilizing a combination stripper and holddown unit, wherein the unit is carried by and is axially movable relative to a rotatable turret, the axial movement of the unit being provided by a yoke member which itself is spring carried by a ram adaptor for vertical movement relative thereto.

LII

Other objects and advantages of the present invention will be readily apparent to one skilled in the art, from the following brief figure descriptions, detailed descriptions of the preferred embodiments, and the appended claims.

IN THE DRAWINGS FIG. 1. is a fragmentary vertical sectional view, taken through a single station punch press of this invention, wherein the mounting ofa stripper-holddown unit to the machine itself is clearly illustrated;

FIG. 2 is a bottom view of the punch head of the punch press illustrated in FIG. 1, taken generally along the line II-II of FIG. 1, with portions broken away and in section for purposes of clarity;

FIG. 3 is a fragmentary vertical sectional view through the punching tool, die, and stripper-holddown unit of this invention, wherein there is illustrated a stripper cap of the selfpunching type, with the tool being illustrated in phantom in a retracted position, and in full lines in an operative position, wherein the initial downward punching operation of the tool punches out the stripper cap to have a tool-conforming periphery;

FIG.-4 is a fragmentary vertical sectional view through the punching tool, die, spacer and stripper-holddown unit of this invention, generally similar to that of FIG. 3, but wherein a workpiece is disposed between the stripper-holddown unit and die, and wherein a punching-out ofa portion of the workpiece by the punching tool is illustrated.

FIG. Sis an enlarged vertical sectional view through an alternative embodiment of the stripper cap adapted for use with the press of this invention, wherein the stripper cap is of the tool-following type;

FIG. 6 is a fragmentary vertical sectional view through a turret-type punch press of this invention, wherein the stripper plate is illustrated in position above the die, carried by the turret plate, with means being illustrated for actuating the stripper-holddown unit for vertical movement;

FIG. 7 is a fragmentary horizontal sectional view, through the punch press of FIG. 6, taken generally along the line VII-VII of FIG. 6, wherein the turret plate is illustrated in plan view, and the yoke-shaped holddown actuation means is illustrated in section; and

FIG. 8 is a fragmentary vertical sectional view through the punch press of this invention, illustrating generally the components illustrated at the lower end of FIG. 6, but wherein the stripper-holddown unit is in clamping engagement against the workpiece, with the punching tool being illustrated in one stage ofits punching operation.

Referring now to the drawings in detail, reference is first made to FIG. 1, wherein there is illustrated a punch press generally designated by the numeral 10, the press comprising a machine 11, a punching tool 12, and a tool adaptor 13.

The machine 11 includes a vertical movable cylindrical ram 14, being generally downwardly movable toward a die 15, the die 15 being generally fixedly positioned with respect to the ram 14. The various machine frame components by which the ram 14 and die 15 are supported are not illustrated herein, for the sake of clarity.

A ram adaptor 16 is provided, being generally of inverted hat-shaped section, having a lower ram seating portion 17, a generally tubular wall portion I8, and a radially outwardly extending flange portion 20. The outer peripheral surface 21 of the tubular portion 18 of the ram adaptor 16 is generally smoothly contoured, for a sliding lit with an inner bore 22 ofa mounting plate 23, the mounting plate 23 being disposed about the adaptor 16 for vertical sliding movement relative thereto.

A plurality of screws 24 are provided, equidistantly circumferentially spaced about the flange 20 of the ram adaptor 16 and the mounting plate 23, for equally balancing pressures exerted on the mounting plate 23 from associated springs 25 disposed about and carried by the screws 24. The springs 25 are in engagement against an upper surface 26 of the mounting plate 23, and in engagement with a lower surface 27 of the ram adaptor flange 20, for biasing the mounting plate 23 downwardly. The screws 24 have threaded lower end portions 28, engaged within correspondingly tapped holes 30 of the mounting plate 23, and heads 31 received within counterbores 32 of the flange 20. The shank 33 of each of the screws 24 is freely slidable within a bore 34 of the flange 20, the screws 24 thus being adapted to limit the vertical downward movement of the mounting plate 23, by engagement of the screw heads 31 against the ram adaptor flange 20, thereby providing double action for the ram head and a resilient seating for the workpiece clamping means later to be described.

The ram adaptor 16 is connected to the ram 14 by a cap headed screw 35 threadably connected within a tapped hole 36 of the ram 14, and in engagement with the seating portion 17 of the ram adaptor 16.

The punching tool 12 is illustrated to be of rectangular configuration, but any suitable configuration may be used. The tool 12 is receivably engaged within its adaptor 13, by conventional means, and the adaptor 13 has an upper boss portion 37 receivably engaged within a bore 38 of the ram adaptor seating portion 17. The tool adaptor 13 also includes a peripheralmost portion 40 which is received within a bore 41 of a connection plate 42, the connection plate being secured to the seating portion 17 of the ram adaptor 16 by suitable screw fasteners 43 or the like. An annular groove 44 is provided about the periphery of the portion 40 of the tool adaptor 13, for engagement therein of one end of a horizontally disposed screw 45, which is threadably engaged within the connection member 42, and is radially outwardly movable with respect to the tool adaptor 13, to a position in which the innermost end of the member 45 clears the annular groove 44 of the adaptor 13, for removal of the adaptor 13, and attached tool 12 from the connection member 42 and ram adaptor 16. The member 42 has a plurality of equidistantly circumferentially spaced slots 39, for selectively receiving therein a pin 49 carried by the adaptor 13, for locking the adaptor 13 in a desired position of angular orientation about its vertical axis.

The stripper-holddown assembly 46 includes a spacer member 47 and a lower dishlike member 48 carried thereby. The spacer member 47 has an upper flange 50 which is connected to the plate 23 by suitable screw-type fasteners 51 (iilustrated in dotted lines in FIG. 1).

A lower flange S2 is disposed beneath the upper flange 50 of the spacer member 47, being rigidly spaced therefrom and connected thereto by means of a pair of vertically disposed

spacer bars

53 and 54 to enable the dishlike plate member 48 to vertically span the tool and tool adaptor as shown in FIG. 1.

The lower flange portion 52 of the spacer member 47 is of generally annular configuration, and has a lower and inner cutout portion 55, which receives the dishlike member 48, in upwardly abutting engagement therein. The dishlike plate member 48 may be maintained in lateral position by spring plunges 56, in resilient engagement against V-shaped detent grooves or the like, 57 in the outer periphery of the dishlike member 48. The member 48 is retained in vertical position by screws 58, which are threadably engaged within the spacer flange 52, the heads of which are each in engagement with a retainer 60. Each retainer 60 is longitudinally slotted at 61 for movement toward and away from the longitudinal central axis (not shown) of a punching tool 12, each retainer 60 also being provided with an upwardly disposed stop 61, for limiting the inward movement thereof.

The dishlike member 48 includes a depending boss 62, which is internally threaded at 63, and in which is engaged a stripping cap 64. The stripping cap 64 has a central portion 65, of predetermined thickness, terminating in a lower planar surface 66 which is substantially flush with the lower planar surface portion 67 of the boss 62 of the dishlike member 48. The central portion 55 of the stripping cap 64 generally provides the stripping edges, with the surface 67 of the boss 62 generally transmitting holddown pressure to a workpiece (not shown) disposed between the surface 67 of the boss 62 and an upper surface 68 of the die 15.

The die 15 is provided with suitable undercutting edges 70, which substantially conform to the outlining configuration of punching tool 12.

It is thus readily seen, that the spacer member 47 and dishlike member 48 of the combination stripper-holddown assembly 46 are carried completely free of and spaced from the tool 12 and its adaptor l3, and that ready access is provided to the screw 45, between the

flanges

50 and 52 of the spacer 47, for retracting the screw 45 and permitting downward movement of the tool adaptor 13, for removal of the same. In order to facilitate such removal of the tool 12 and too] adaptor 13, the stripping cap 64 may be threadably disengaged from the threads 63 of the boss 62, and the ram 14 moved upwardly away from the upper surface 68 of the die 15, in order to completely remove, and/or replace the tool 12 and adaptor 13 with another tool and adaptor, as for example, in changing tool size or shape, and for adaptability in receiving tooling of various manufacturers and the like,

The ready removal of the dishlike member 48 from the lower flange 52 of the spacer 47 provides a primary feature, for easy removal of the tool 12 and adaptor 13, if such is desirable, by retracting the retainers 60 to their outermost positions relative to the vertical axis of the tool 12, followed by downward movement of the dishlike member 48 of the eutout 55.

With reference to FIG. 3, there is illustrated the manner in which the punching tool 12 is moved vertically downwardly, during an initial punching operation, with the stripper-hold down assembly 46 in engagement against an upper surface 68 of the lower die 15, and with the

lower surfaces

66 and 67 of the plug 64 and boss 62 in substantially flush engagement against the upper surface 68 of the die 15. The tool 12 is brought into engagement against the central portion 65 of the plug 64, and shears the central portion 65 therefrom, to have an outlining configuration substantially equilivant t0 the configuration of the punch 12 and die cutting edges 70. The punch 12 is then retracted, and the stripper is then ready to perform a stripping function.

Referring now to FIG 4, there is illustrated one stage of the punching operation, with a workpiece W disposed on the upper surface 68 of the die 15, and clamped thereagainst by the force of the spring 25 exerted through the stripper-holddown assembly 46, with the newly cut outlining lip 71 of the plug 64 being adapted to strip punched material M away from the tool 12, during an upward retraction of the tool 12, after completion ofa punching operation on the workpiece W.

With particular reference to FIG. 5, there is illustrated an alternative embodiment of a stripper cap 72, illustrated in a threaded engagement within a boss 73 (illustrated in phantom) of a dishlike member, generally similar to that 48 illustrated in FIG. 1. The stripper cap 72 includes a carrier portion 74, having a clearance bore 75 therein and an outer threaded portion 76, terminating in a lower workpiece engaging surface 77. An insert 78, of the desired thickness is disposed inwardly of the retainer portion 74 of the cap 72, being inserted therein from beneath, and retained in place by any suitable means, such as the snap-ring fastener 80. The insert 78 is thus retained to be rotatably movable within the major portion 74 of the cap 72, such that, if the tool and tool holder to be used therewith is angularly rotated about its vertical axis (not shown) while the tool 12 is still disposed within the insert 78, the insert 78 will also be rotated to the new position of the tool, in order to provide stripping for the tool in the newly selected angular position thereof. It will be understood that the annular groove 44 in the tool adaptor 13 facilitates the positioning of the tool 12 to a various number of positions about its vertical axis.

With reference to FIG. 6, there is illustrated a portion of a turret type punch press machine, generally designated by the numeral 85, having a stripper-holddown unit 86 carried thereby. A punching tool 87, and its adaptor 88 are illustrated,

in removed and unsupporting relation with respect to the stripper-holddown unit 86.

The machine 85 includes a ram 90, movable vertically downwardly toward a lower die 91, both the ram 90 and lower die 91 being fixed, except for relative vertical movement. A ram adaptor 92 is provided, carried by the ram 90, generally similar to the ram adaptor 16 of FIG. 1, and a mounting plate 93 is slidably carried about a tubular surface portion 94 of the ram adaptor, being resiliently urged downwardly by suitable compression springs 95. A plurality of screws 96 provide motion limiting means, to limit the downward movement of the mounting plate 93, relative to the upper portion of the ram adaptor 92.

At the lowermost end of the ram adaptor 92, there is provided an arcuately slotted groove 97, which is undercut to receive therein a head 98 of the tool adaptor 88.

The tool 87 is vertically slidable within a rotatable turret plate 100, the turret plate 100 being adapted for rotation about its central axis (not shown), in the direction of the arrow of FIG. 7. Thus, the head 98 of the tool adaptor 88, in an uppermost position of the tool 87 within its turret plate bore 101, is adapted for registration within the undercut arcuate groove 97, and when the tool 87 is disposed directly beneath the vertical axis of the ram 90, the arcuate movement of the turret plate 100 will be discontinued, leaving the tool 87 and its adaptor 88 in position for vertical actuation by the downwardly moving ram 90 and ram adaptor 92.

The stripper-holddown unit 86, as illustrated, may be of the plate type, and is normally carried upwardly against the lower surface 102 of the rotatable turret plate 100, being secured thereto by one or more screws 103, for limited vertical movement, but being upwardly biased by compression springs 104.

When it is desired to perform a punching operation, a workpiece WP is disposed on the upper surface of the die 91, and the ram 90 is actuated for vertical downward movement. The mounting plate 93 also moves vertically downwardly, carrying a vertical member 105 and a horizontal member 106; the mounting plate 93, vertical member 105, and horizontal member 106, cooperating to form a yoke-shaped or C-shaped actuation means, for transmitting vertically downwardly moving forces to the stripper-holddown unit 86 but serving to span the tool and tool adaptor as shown in FIG. 6. Thus, upon actuation of the ram 90, the horizontal member 106 will engage the stripper-holddown unit 86 and move the same into clamping engagement against the workpiece WP, under a force provided through the springs 95, upon continued downward movement of the ram 90, and consequent downward movement of the punching tool 87, until the workpiece WP is punched as desired, as illustrated in FIG. 8. The ram 90 may then be retracted with the springs 95 acting through the yokeshaped composite member to retain the stripper-holddown 86 against the workpiece, until the tool 87 is completely retracted, and the stripping edges 108 of the stripper-holddown unit 86 have stripped the punched material M from the punch 87.

Continued upward retraction of the ram 90 will permit the mounting plate 93, the vertical member 105 of the yoke, and the horizontal member 106 to move vertically upwardly, to release the clamping force from the stripper-holddown unit 86, and consequently from the workpiece WP.

The rotatable turret plate may then be rotated about its axis (not shown) in the direction indicated by the arrow in FIG. 7, with the head 98 of the tool adaptor 88 passing through the undercut arcuately slotted groove 97, to clear the same, whereby a next adjacent tool carried by the turret 100 may be brought into position beneath the ram 90.

It will be observed that the bottom surface 102 of the turret plate 100 may be undercut, as at 108, in order to receive the horizontal member 106 therein, for engagement of the horizontal member 106 with the stripper-holddown 86. In the alternative, some means (not shown) may be provided for selectively moving the horizontal member 106 away from and beneath the turret plate 100, upon indexing of a tool 87, to position.

It will also be noted that the stripper-holddown 86 has been illustrated as comprising a single plate, but that the same may be threaded for receiving a stripper cap. as for example that iilustrated in FIG. 1, or, as for example that illustrated in FIG. 5, wherein stripping edges of the stripper cap thus utilized would function in substantially the same manner as the stripping edges 107 ofthe stripper-holddown unit 106.

Various modifications may be made in the details of construction, materials, and the sequence of operation of the punch presses of this invention, all within the spirit and scope of the invention, as defined in the appended claims.

It will also be apparent that this invention is not limited to the particular types of punching operations and punch presses disclosed but is adapted for using in notching and nibbling operations, and the like, in addition to hole punching operations.

As a further alternative, the dishlike member 48 may be retained in vertical position within the spacer member 47 by horizontally disposed spring-loaded plungers or the like, carried by the spacer member 47 and engaged within blind bores in sides of the dishlike member 48, the member 48 being retained against undesirable angular movement by vertically disposed dowels carried by the spacer member and engaged within mating holes of the dishlike member.

It will be understood that the Abstract of the Disclosure" provided herein is intended to be a nontechnical description of the invention, in order to comply with the Rules of Practice of the Patent Office, and is in no way intended to limit the scope of the invention as defined in the claims.

I claim:

1. A punch press apparatus comprising a punch machine, including'means for driving a tool, a punching tool, a tool adaptor, a combination stripper-holddown unit, a spacer, and means for mounting said spacer on said machine free of attachment to and lateral support from either of said tool adaptor and said tool, for facilitating removal and replacement of variously sized tools without disconnection or replacement of said spacer relative to said machine, said spacer being vertically rigid between said unit and said mounting means, being configured to vertically span the tool and tool adaptor in the retracted position of the tool while maintaining the stripperholddown unit spaced from the mounting means, and being disposed for moving said holddown unit into engagement with a workpiece under a desired force applied from said tool driving through said spacer in the punching position of the tool.

2. The apparatus of claim 1, wherein said tool driving means includes a ram and ram adaptor for transmitting driving forces to said tool through said tool adaptor, said spacer and said unit being resiliently vertically driveable by said ram adaptor.

3. The apparatus of claim 2, wherein said apparatus is of the single station type. v

4. The apparatus of claim 3, wherein fastening means are carried by said ram adaptor for releasably disengaging said tool adaptor from said ram adaptor.

5. The apparatus of claim 4, wherein said unit is provided with laterally opening access means for manually actuating said fastening means.

6. The apparatus of claim 2, wherein said apparatus is of the turret type.

7. The apparatus of claim 6, wherein said machine includes a rotatable turret plate, and said mounting means connects said unit to said turret plate for vertical movement relative thereto.

8. The apparatus of claim 7, wherein said turret plate houses a plurality said tools for vertical movement therein, said tool adaptor being secured to said tool and being laterally engageable with said ram adaptor for vertical driving actuation thereby.

9. The apparatus of claim 7, wherein said spacer is generally yoke-shaped in vertical section for transmitting unit-driving forces from above said turret plate to said unit located therebeneath.

10. The apparatus of claim 1, wherein said unit has a planar holddown surface means for clampingly' engaging a workpiece surface in outlining relation to a workpiece portion to be engaged by said tool.

11. The apparatus of claim 10, wherein a readily removable stripper cap is provided, comprising a part of said unit, said cap having surface means thereon substantially in conformity with the peripheral configuration of said tool, and in substantially the same horizontal plane as said holddown surface means.

12. The apparatus of claim 11, wherein said cap is of the self-punching type, for formation of its stripping periphery by an initial downward stroke of said tool.

13. The apparatus of claim 11, wherein said cap has a rotatable inner portion for following angular rotation of said tool about its vertical axis.

14. A punch press apparatus comprising a punch press machine including means for driving a tool, a punching tool, a tool adaptor, a combination stripper-holddown unit, a spacer, and means for mounting said spacer on said machine free of attachment to and lateral support from either of said tool adaptor and said tool, for facilitating removal and replacement of variously sized tools without disconnection or replacement of said spacer relative to said machine, wherein said tool driving means includes a ram and ram adaptor for transmitting driving forces to said tool through said tool adaptor, and said spacer and said unit being resiliently vertically driveable by said ram adaptor, wherein said apparatus is of the single station type, wherein said mounting means comprises a plate member disposed about and carried by said ram adaptor and vertically movable relative thereto, said unit comprising a dishlike member removably connected to said spacer.

15. The apparatus of claim 14, wherein said spacer carries horizontally movable plunger means for engagement in recesses at sides of said dishlike member and for fixing the lateral position of said dishlike member within said spacer.

16. The apparatus of claim 14, wherein said spacer carries horizontally slidable clamping means for clamping said dishlike member within said spacer in a fixed vertical position relative to said spacer.

17. The apparatus of claim 14, wherein said spacer carries quick release horizontally movable plunger means for retaining said dishlike member within said spacer.

18. A punch press apparatus comprising a punch press machine including means for driving a tool, a punching tool, a tool adaptor, a combination stripper-holddown unit, a spacer, and means for mounting said spacer on said machine free of attachment to and lateral support from either of said tool adaptor and said tool, for facilitating removal and replacement of variously sized tools without disconnection or replacement of said spacer relative to said machine, wherein said tool driving means includes a ram and ram adaptor for transmitting driving forces to said tool through said tool adaptor, and said spacer and said unit being resiliently vertically driveable by said ram adaptor, wherein said apparatus is of the single station type, wherein fastening means are carried by said ram adaptor for releasably disengaging said tool adaptor from said ram adaptor, including an annular groove means in said tool adaptor for selective positioning of said tool in a plurality of annular positions about a vertical tool axis, said fastening means being engageable within said annular groove means of said tool adaptor.