US3160046A

US3160046A - Multiple die punches with stripper means

Info

Publication number: US3160046A
Authority: US
Inventors: Bredow Walter
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-08-30
Filing date: 1962-08-20
Publication date: 1964-12-08
Anticipated expiration: 1981-12-08
Also published as: GB950807A; DE1176964B

Description

W. BREDOW Fig. l

MULTIPLE DIE PUNCHES WITH STRIPPER MEANS Dec. 8, 1964 Filed Aug. 2o, 1962 Dec. 8, 1964 w. BREDow 3,160,046

MULTIPLE DIE PUNCHES WITH STRIPPER MEANS Filed Aug. 20, 1962 2 Sheets-Sheet 2 Fig.2

United States Patent aimais Mum-"man um nurseries wrrn stemma ift/mans Walter Bretten', Vormaseli 2, Alteld, Germany Filed Aug, 20, 1962, Ser. No. 217,9t- Claims priority, application Germany, Aug. 30, 196i, il 65,844 1t? Claims. (Cl. 8313tl) The present invention relates to the equipment of the upper turret plate, especially of multiple die punches, with a controlled centre clamp holder and stripper, the design of which is such that this centre clamp holder and stripper may adjust itself to various gauges of sheet metal to be punched.

According to the invention, there is arranged under the turret plate, and preferably under the upper turret plate, a holding and Astripping plate, the movement of which precedes that ot the punching tool or tools and which holds the material in position until the punching tool has been withdrawn from the workpiece. The movement of the holding and stripping plate may be eiiected by the same members which also control the movement of the punching tool or tools.

Y In a preferred embodiment of the invention, there is arranged between the upper turret plate and the holding and stripping plate a compressible body or medium in suitable compression cylinders. Such compressible bodies are, for example, helical springs, plate springs, annular springs or parts made of rubber.

The invention also relates to the various members required either in order to t a compressible energy accumulator, or necessary in order to correlate the movements of the turret plate and the punching tools on'one hand, and the movement of the holding and stripping plate on the other hand. Y

The invention has the advantage that the holding and stripping member can adapt itself automatically to various thicknesses of the sheet metal to be punched, and that the material is held down already prior to the punching and is held in this position until the tool is withdrawn from the workpiece. Thus all forces are eliminated which aiect only the itself and its guides and which thus support or accelerate wear of tools and machine. Furthermore, also the operation is much easier, because the operator need not observe the behaviour of the workpiece as closely as hitherto.

The invention will be further described, by way of example, with reference to the accompanying drawing, showing two embodiments. in the drawing:

FIG. 1 is a cross-section of the turret plate, the resilient member being formed by a spring stack located in the guide column ofthe upper turret plate.

FlG. 2 is a further embodiment, in-which the resilient member is located between the upper turret plate and the holding and stripping plate.

The upper turret plate 1 and the lower turret plate Z are mounted by means of their

spindles

3 and 4 in the machine frame or tool holder 5.

The upper turret plate 1 contains the displaceable die holder 6, connected in the punching position with the ram 7, and moved thereby during the punching in a downward direction; during the upward movement, the die holders 6 and the dies l0' and 1li" mounted therein are again withdrawn from the punched workpiece.

The positively controlled holding and stripping plate 8 is mounted by means of its guide column 9 in the spindle 3 of the upper turret plate 1 in a displaceable manner. The movement of the holding and stripping plate 3 whereby the same is placed on to the material to be punched, is advanced relative to the movement ot the r*ICC actual die lil or lil, mounted in the die holder 6. This holding and stripping plate may be operated, for example, by an eccentric 15 on the driving shaft 25, or a lever linkage coupled with the drive 16 for the ram 7. The stripping plate may also be operated pneu'matically or hydraulically. f

The holding and stripping forceis supplied by an energy accumulator 11, for example, a biased stack of plate springs il, iitted into the guide column and so dimensioned that it produces the maximum required stripping etfort. v

The eiiect of the springs 11 is caused by the fact'that they are located between the ram 25 With the head 27 and the guide column, and the ram is located displaceably in the column 9, whilst the ram pin 2S is guided at its lower end in a recess 29. Y

The parcels of plate springs `11 may also be replaced by other energy storage means, such as helical springs, annular springs, rubber springs, or springs made from rubber-like materials, as well as compressible gases iu suitable compression cylinders. Y

The energy accumulator may also be located at another point of the transmission for operating the holding and stripping plate 8. Y Y

This holding and stripping plate 8 acts in that way that, when the punching process is initiated, the plate advances in front of the die holder 6 or punch lil or lil so that the actual strippers fitted into the holding and stripping plate are placed on the material to be machined. During this movement, the energy accumulator is biased beyond its normal bias. Simultaneously, the die holder 6 with the die lil or itl carries outthe punching. During the upward movement of the die holder 6 with the die lil or iii, the strippers remain rst on the punched material until the` spring stack has been destressed to its normal bias. Since the holding and stripping plate 8, and the strippers i4 rest under spring action on the punched material, the die iti or itl may be withdrawn without lifting the workpiece itself.

Since the holding and `stripping plate 8 is not positively connected through the energy accumulator with the actuating mechanism, there are provided, for example, springs 12, for returning the stripper plate 3 to its loriginal position. The spring bolts i3 simultaneously act as guide pins to secure the stripper plate 8 against rotation relative to the upper turret plate 1.

FIG. 2 shows another solution, embodying the principle of the invention.

The positively controlled holding and stripping plate 8 is also in this case located displaceably by means of its guide column 9 in the spindle 3 of the upper turret plate i, and also here, the movement whereby the stripper plate 8 is placed on the material to be punched, is advanced relative to the movement of the die 1d', 19, mounted in the die holder 6. However, in this embodiment, the holding and stripping pla-te S is moved by means of the sloping plane 2l, located on the pull rod 20, -for driving the ram through a toggle mechanism, whereby the guide column 9 is-lifted and lowered.

During the downward movement of the ram 7 for the punching process, the holding and stripping plate 8 also moves towards the workpiece and rests thereon before the actual punching starts. Due to the lateral movement of the pull rod 2) in association with the sloping plane 2li, the guide column 9 of the holding and stripping plate 8 is released for the downward movement. During the continued downward movement of the ram 7 with the die holder 6 and the die lil or lil", the actual punching is performed. Y

Also here, the holding and stripping force is supplied by energy accumulators, preferably biased plate spring stacks di, located between the upper turret plate 1 and the holding and stripping plate 8, the compression of these springs being so dimensioned as to produce the maximum required elort. These plate springs are merely shown diagrammatically.

The stripper plate 3 is secured against twisting relative to the upper turret plate 1 by guide pins 22 which also deline the movement of' the holding and stripping plate S towards the upper turret plate 1.

During the upward movement of the die 16 or lil, the holding and stripping plate 8 with the strippers 14 remainsA on the material until the die has been withdrawn against the pressure of the energy accumulator 41, and only then is the holding and stripping plate S lifted through its guide column 9, by means of the sloping guide plane 21 on the pull rod 2li.

The guide plane 21 is so designed and formed that the holding and stripping plate precedes the tool 18 or 10 during the downward movement of the same, and remains on the material during the upward movement of the tool lil or 1li until the same has ybeen withdrawn from the material.

The action of 'the holding and stripping plate S with tted strippers 14 according to the invention corresponds to that of a cutting tool with itted resilient holder and stripper.

The guide plane 21 may cause the vertical movement control of the guide column, for example by means of a roller 32 located at the upper end of the guide column 9 and rolling during the actuation of the pull rod 26 along the guide plane 21.

What I claim is:

1. Rotary punch press including a frame having upper and lower parts, a spindle supported in the upper frame part, an upper revolving turret plate on the spindle, a lower revolving turret plate coaxially journalled in the lower frame part, a plurality of aligned pairs of tools carried by the plates, the plates being rotatable together to bring a desired pair of tools yto a working position, a stripper and hold-down plate below the upper turret plate, a guide column supporting the stripper and holddown Vplate and axially slidable in the spindle, means for preventing rotation of the stripper and hold-down plate relative to the upper turret plate, drive means for lowering and raising a tool carried by the upper turret plate at the working position, and means for concurrently lowering and raising the stripper and hold-down plate, the downward motion of the latter plate preceding that of the upper turret plate and the upward motion of the said latter plate succeeding that of the upper turret plate.

2. Rotary punch press including a frame having upper and lower parts, a hollow spindle supported in the upper frame part, an upper revolving turret plate on the spindle, a lower revolving turret plate coaxially journalled in the lower frame part, a plurality of aligned pairs of tools carried by the turret plates, the turret plates being rotatable together to bring a desired pair of tools to a working position, a stripper and hold-down plate below the upper turret plate, a guide column supporting the stripper and hold-down plate, the guide column being axially slidable in the spindle, at least one guide pin coupling the upper turret plate and the stripper and hold-down plate for preventing relative rotation of the said plates, a plurality of stripping means on the stripper and holddown plate corresponding to the said ltools, drive means for lowering and raising a tool carried by the upper turret plate at the said working position, and means for concurrently lowering and raising the stripper and holddown plate, the downward motion of the latter plate preceding that of the upper turret plate and the said latter plate remaining in contact with a workpiece disposed on the lower turret plate until the tool leaves the workpiece on its upward stroke.

3. Rotary punch press including a frame having upper and lower parts, a hollow spindle supported in the upper frame part, an upper revolving turret plate on the spin- 4 ldle, a lower revolving turret plate coaxially journalled in the lower frame part, a plurality of aligned pairs of tools carried by the turret plates, the turret plates being rotatable together to bring a desired pair of tools to a working position, a stripper and hold-down plate below the upper turret plate, a guide column supporting the stripper and hold-down plate, the guide column being axially slidable in the spindle, at least one guide pin coupling the upper turret plate and the stripper and holddown plate for preventing relative rotation of the said plates, a plurality of stripping means on the stripper and hold-down plate corresponding to the said tools, drive means for lowering and raising a tool carried by the upper turret platek at the said working position, and means for concurrently lowering and raising the stripper and hold-down plate, the downward motion of the latter plate preceding that of the upper turret plate and the said latter plate remaining in contact with a workpiece disposed on the lower turret plate until the tool leaves the workpiece on its upward stroke, the said means for raising and lowering the .stripper and punch plate including a rotating shaft forming part of the said drive means, an

eccentric on the shaft and acting on the said guide col-` umn to lower ythe stripper and hold-down plate concurrently with a tool at the said working position, and resilient means acting between the upper turret plate and the stripper and hold-down plate to bias the plates towards one another.

4. Rotary punch press as claimed in claim 3, the said guide column being open upwardly, and further including a plunger axiallyslidable in the guide column and bearing on the eccentric, and resilient energy accumulating means disposed between the plunger and the guide column to transmit axial forces therebetween.

k5. Rotary punch press including a frame having upper and lower parts, a hollow spindle supported in the upper frame part, an upper revolving turret plate on the spindle, a lower revolving turret plate coaxially journalled in the lower frame part, a plurality of aligned pairs of tools carried by the turret plates, the turret plates being rotatable together to bring a desired pair of tools to a working position, a stripper and hold-down plate below the upper turret plate, a guide Vcolumn supporting the stripper and hold-down plate, the guide column being axially slidable in the spindle, at least one guide pin coupling the upper turret plate and the stripper and hold-down plate for pre,

venting relative rotation of the said plates, a plurality of stripping means on the stripper and hold-down plate cor responding to the said tools, drive means for lowering and raising a tool carried by the upper turret plate at the said working position, and means for concurrently lowering and raising the stripper and hold-down plate, the downward motion of the latter plate preceding that of the upper turret plate and the said latter plate remaining in contact with a workpiece disposed on the lower turret plate until the tool leaves the workpiece on its upward stroke, the said means for lowering and raising the stripper and hold-down plate including a rotating shaft forming part of the said drive means, a plunger axially slidable in the upper end of the guide column and projecting therefrom and bearing on the said eccentric, compression spring means disposed between the plunger and the guide column to transmit axial forces therebetween, whereby rotation `of the said shaft causes the eccentric to act on the guide column via the plunger to lower the stripper and hold-down plate in advance of the downward movement of the tool resulting from said rotation.

6. Rotary punch press according to claim 5, including resilient means acting to bias the stripper and hold-down plate towards the upper turret plate.

7. Rotary punchr press according to claim 6, in which the said resilient means consist of springs disposed on the said guide pins.

8. Rotary punch press including a frame having upper and lower parts, a hollow spindle supported in the upper frame part, an upper revolving turret plate on the spindle, a lower revolving turret plate coaxiallyjournalled in the lower frame part, a plurality of tools carried by the turret plates and disposed in aligned pairs, means for rotating the turret plates together to bring any pair of tools to a working position, a rotatable stripper and hold-down plate disposed below and coaxially with the upper turret plate, a guide column supporting the stripper and holddown plate and axially slidable in the said spindle, means for preventing rotation of the stripper and hold-down plate relative to the upper turret plate, a plurality of stripping means on the stripper and hold-down plate corresponding to the said tools, drive means for lowering and raising a tool carried by the upper turret plate at the said working position, a cam moving with the said drive means and co-operating with the said guide column to lower and raise the stripper and holddown plate concurrently with the said tool, the downward movement of the stripper and hold-down plate preceding that of the tool and the said plate remaining in its lowered position until after disengagement of the tool from a workpiece disposed on the lower turret plates corresponding tool.

9. Rotary punch press including a frame having upper and lower parts, a hollow spindle supportedrin the upper frame part, an upper revolving turret plate on the spindle, a lower revolving turret plate coaxially journalled in the lower frame part, a plurality of aligned pairs of tools carried by the turret plates, the turret plates being rotatable together to bring a desired pair of tools to a working postion, a stripper and hold-down plate below the upper turret plate, a guide column supporting the stripper and hold-down plate, the guide column being axially slidable in the spindle, at least one guide pin coupling the upper turret plate and the stripper and hold-down plate for preventing relative rotation of the said plates, a plurality of stripping means on the stripper and hold-down plate corresponding to the said tools, drive means for lowering and raising a tool carried by the upper turret plate at the stroke, the said means for lowering and raising the stripper and hold-down plate including a linearly moving rod forming part of the said drive means, an inclined plane on the said rod acting on the said guide column to lower and raise the stripper and hold-down plate concurrently with the tool motion resulting from movement of the-rod.

10. Rotary punch press as claimed in claim 9, in which the said drive means is a toggle mechanism actuated by the said rod and the said inclined plane is provided on the upper side of the said rod, the guide column extending upwards to a level above the said plane, and further including a cam follower on the upper end of the guide column resting on the said inclined plane, and resilient means disposed'between the upper turret plate and they References Cited by the Examiner UNITED STATES PATENTS 854,706 5/07 Eden 83-132 921,068 5/09 Bertsch et al 83-135 1,781,000 11/30 De Beaulieu 83-552 1,940,883 12/33 Rollings 83-552 2,168,377 8/39 Wales 83-140 2,268,787 l/42 Wales 83-140 2,329,061 9/43 Kopczynski 83-140 2,378,603 6/45 Wales 83-132 2,647,578 8/53 Connor et al. 83-138 2,701,017 2/55 Wiedemann 83-552 2,732,898 1/56 Taylor 831-137 2,778,426 1/57 Taylor 83-138 2,805,717 9/57 Taylor 83--139 3,049,038 8/62 Friedland 83-552 LEON PEAR, Primary Examiner.

HUNTER C. BOURNE, IR., Examiner.

Claims

1. ROTARY PUNCH PRESS INCLUDING A FRAME HAVING UPPER AND LOWER PARTS, A SPINDLE SUPPORTED IN THE UPPER FRAME PART, AN UPPER REVOLVING TURRET PLATE ON THE SPINDLE, A LOWER REVOLVING TURRET PLATE COAXIALLY JOURNALED IN THE LOWER FRAME PART, A PLURALITY OF ALIGNED PAIRS OF TOOLS CARRIED BY THE PLATES, THE PLATES BEING ROTATABLE TOGETHER TO BRING A DESIRED PAIR OF TOOLS TO A WORKING POSITION, A STRIPPER AND HOLD-DOWN PLATE BELOW THE UPPER TURRET PLATE, A GUIDE COLUMN SUPPORTING THE STRIPPER AND HOLD-DOWN PLATE AND AXIALLY SLIDABLE IN THE SPINDLE, MEANS FOR PREVENTING ROTATION OF THE STRIPPER AND HOLD-DOWN PLATE RELATIVE TO THE UPPER TURRET PLATE, DRIVE MEANS FOR LOWERING AND RAISING A TOOL CARRIED BY THE UPPER TURRET PLATE AT THE WORKING POSITION, AND MEANS FOR CONCURRENTLY LOWERING AND RAISING THE STRIPPER AND HOLD-DOWN PLATE, THE DOWNWARD MOTION OF THE LATTER PLATE PRECEDING THAT OF THE UPPER TURRET PLATE AND THE UPWARD MOTION OF THE SAID LATTER PLATE SUCCEEDING THAT OF THE UPPER TURRET PLATE.