US2850093A - Perforating apparatus - Google Patents

Description

Sept. 2, 1958 J. D'ANGELO ETAL 2,850,093

PERFORATING APPARATUS 2 Sheets-Sheet 1 Filed Dec. 6, 1955 INVENTOR. JOSEPH D ANGELO y JOSEPH DINUNZIO ATTORNEY is heat-sealed laterally to form the package.

case, if the material is to be perforated it is important 'to do so without tearing the material or otherwise interfering with its normal continuous movement t-hrough the machine.

PERFORATEI G APPARATUS Joseph DAngelo, Flushing, and Joseph Di Nunzio,

Astoria, N. Y., assignors to Roto Bag Machine Corporation, New York, N. Y.

Application December 6, 1955, Serial No. 551,268

9 Claims. (Cl. 164-94) This invention relates to improvements in perforators,

and particularly to an improved'perforator for making holes in a moving web of packaging material.

Among the many uses that have been developed for -plastic materials, there are a number of instances in the packagingindustry and the like where the material must be perforated. For example, in the packaging of certain .vegetables, such as potatoes, it is desirable to make provision for air circulation about the packaged articles to prevent spoilage. This is accomplished most readily -by -making holes in the packaging material, and for economy'it is preferable to do the perforating 'while the materialisgoingthrough some other necessary fabrication procedure such as the formation ofthe packages .or

bags.

' his, of course, common practice to form plastic bags in a continuous-process apparatus wherein the packaging material moves-continuously from a supply roll or the jlike to the finished package discharge point.

in some instances, the material may leave the supplyroll as a flat-web which is subsequently folded and heatsealed longitudinally and laterally to form the package.

In other types of machines, an extruded tube of plastic In any ''It is a general object of the invention to provide a pe'rforator for use in application such as those referred to above. More specificaly, it is among the objects of the invention to provide a perforator which lends itself nism wherein a spherical punch is driven against a sharpedged circular cutting die to perform the cutting operation. To insure uniformity and reproducibility of re sults, the punch is driven by a spring-loaded plunger which is withdrawn against the force of the spring by a cam element. Upon disengagement of the cam, the

- plunger is carried forward by the spring and its forward motion transmitted to the punch to drive the punch against the die. Immediately upon making cutting co tactwith the die, the punch-is released so as not to intates Patent terfere with the movement-of the material, and assumes a-position in readiness for the next punching operation.

-A more complete understanding of the invention and of further objects and features thereof .can he had by reference to the'following descriptionof an illustrative m od m n of t in enti n. when .ccns de in c nection, with the accompanying drawings, in which:

. annually r sts an th p be nsrur n a y to i of the hole 211.

Figure 1 is an elevational view, partly in section, of a perforator embodying the present invention;

Figure '2 is a sectional view of the perforator shown in Figure 1, taken onthe line 2-2 of Figure 1; and

Figure 3 is an enlarged exploded perspective view of 'the'camming members for actuating the punch driver in the perforator of Figures 1 and 2.

As shown in Figure 1 of the drawings, a perforator embodying the invention comprises a bed plate 11) which extends across the path .of travel of the continuously moving material 12 to be perforated. It will be understood that the bed plate'may be mounted at any suitable point along the path of material travel in a complete machine for forming bags or=the like. The present showing is limited solely to those parts which contribute to an understanding of the invention.

A pair of C-shaped punch-and-die support blocks 14 are mounted on a spacer plate 15 at opposite ends of the bed plate 10. The spaces 16 between the upper and lower portions 17, 18 of the blocks 14 provide slots through which the edge portions of the material 12 can pass.

As best shown in Figure 2, guide rollers 19 preferably are 'journalled between brackets 20 extending upwardly from the bed plate 10 ahead of and beyond the blocks 14 in the path of material travel. The material is passed over -'-the rollers 19-to insure its being held flat and properly positioned as it passes through the perforator.

The lower portion '13 of'each C-block 14 carries a *female die'insert 21 which is set flush with the surface ofthe block section '18 ovcr-which the material 12 passes. The die 21 has a central hole ZZtherein Which forms a sharp circular-cutting edge 24hr the upper surface of the 'die. The die hole 22 preferably tapers outwardly somewhat from top to bottom and registers with holes 26, 28 in the spacer 15 and bedplate It) so that the punched out material can drop freely from the die.

Above the die 21 is mounted a punch comprising a ball 29 fitting slidably in a sleeve 30 which is set into the upper portion 17 of the block 14in axial alignment with the die aperture 22. When no material is passing through the perforator, the ball 29 will rest on the cuttingedge 24 of the die, protruding slightly into the hole'22 as the-ball-diameter-is slightly larger than that When material is passing through the C-slot 16, the ball "29 normally will ride lightly on the surface of the moving material, as shown in the drawing.

'The sleeve-3t) in which the ball 29 is located also serves as a guide for an impact transfer member 31.

"This transfermember -3;1 comprises a rod which is slidable vertically in the sleeve 30. In order to allow the ball to ride freely ont'he moving material surface, the rod 31 normallyis held in a retracted position, as shown, by a return spring 32. The spring '32 fits around the rod 31 and extends from a flange 35011 the upper end of the sleeve to the underside of an enlarged diameter cap 33 formed on the upper end of the rod 31.

The punch is actuated by a driver which is mounted above the C-block 14 in a bearing support 34. The support 34 has vertically spaced upper and lower sections 36, 37 which project over the transfer memer 31 and carry slide bearings 38,69 for a vertically reciprocable plunger 4t which is axially aligned with the transfer rod 31. The underside of'the lower, support section 37 serves as .a stop for limiting upward movement of the rod 31,

being contacted by the cap 33 when the rod is in its rest position as shown.

The lower end of the plunger 40 is slightlyrounded t0. s erve Vas-.,a.hammer head .for strikingthecapSS, and

this positionhy. a drive-spring"4- 2. .Thespring42extends between the underside of the upper support section 36 and an adjusting collar 43.which is threaded onto the upper portion of the plunger 40. The upper portion of the plunger 40 also is enlarged slightly to form a shoulder 41 on the plunger. During operation of the perforator, the shoulder 41 will bottom against a flange 44 formed at the upper end of the lower bearing 39 to limit the downward movement of the plunger. The collar 43 provides a means for adjusting the effective force of the spring 42 so that it can be properly balanced with the opposing force of the return spring 32, as described hereinafter.

The enlarged upper portion of the plunger 40 also is slotted as indicated at 45 (Figure l) to accommodate a dowel pin 46 extending laterally through the slot 45. The pin 46 prevents rotation of the plunger to insure proper orientation of the plunger with respect to the plunger actuator, which will now be described.

The plunger 40 is actuated by raising it against the force of the drive spring 42 and then releasing it to be driven downwardly by the spring 42. The plunger actua tor or lift comprises a rotatable shaft 49 journalled above the punch mechanism in bearing brackets 50 which extend upwardly from the bedplate 10 beside the C-blocks 14. A gear 51 keyed to the end of the shaft 49 is engaged by a drive gear 52 for rotation by any suitable drive mechanism (not shown). A pair of discs 53 are fixed to the shaft 49 immediately adjacent to the plungers 40. Each disc 53 carries a plurality of cam elements 54 distributed about the periphery of the face of the disc and projecting from the disc surface a sufficient amount to engage the complimentary bevelled undersurface 48 (see also Figure 3) of a projecting lug 48 at the upper end of the associated plunger 40. Accordingly, upon rotation of the shaft 49, each cam 47 in turn will engage the lug 48 of its associated plunger 40, raising the plunger away from its impact transfer rod 31 against the force of the associated drive spring 42. In the position shown in the drawing, the plunger is partially raised. As the cam slides out from under the lug 48, the plunger 40 will be released and driven downwardly by the spring 42 to strike the rod cap 33. In turn, the rod 31 will be driven downwardly against the 'ball 29, driving the ball into temporary cutting engagement with the rim 24 of the die aperture 22 and thereby perforating the moving material.

Immediately upon completion of this cutting contact,

the rod 31 and plunger 40 will be raised by the return spring 32, freeing the ball 29'. The moving material will slide between the ball and the die, and the ball will ride freely on the moving material surface until the next punching operation.

For simplicity, the foregoing description has been given mainly in terms of a single punch and associated parts, it being understood that the two punch assemblies shown will operate in substantially identical fashion and that holes can be made either simultaneously or alternately in the opposite edges of the moving material depending on the number and relative orientation of the earns 54 on their associated discs.

It may be noted that the momentum developed by the plunger 40 in its downward movement must be suflicient to overcome the resistive force of the return spring 32 in order for the proper cutting impact to be delivered to the ball point 29. At the same time, the force exerted by the return spring 32 when compressed must be adequate to overcome the downward force of the drive spring 42 when the latter is extended, so as to return the rod 31 and plunger 40 to their rest positions promptly. These forces can readily be balanced by proper initial selection of the plunger mass and spring specifications, with any necessary final adjustment being made by adjusting the collar 43 to vary the force exerted by the drive spring 42.

It can be seen that the unique perforator assembly described in the foregoing, wherein the actuating force for the punch is dependent solely on the setting of the drive spring 42, completely eliminates any variation in this actuating force such as might occur if the driving force were supplied by having the cams act as hammers, for example, in which case the drive force would vary with variations in the speed of rotation of the shaft. Thus, it is apparent that the present invention provides a perforator that will operate in a highly precise and reliable manner.

What is claimed is:

1. An improved perforator for making holes in a continuously moving web of packaging material, said perforator comprising a die having a hole therein forming a sharp circular cutting edge in the surface of said die, a punch movable toward and away from said die and having a spherical surface portion engageable with said circular cutting edge, the radius of curvature of said spherical surface portion being larger than the radius of said circular cutting edge, a reciprocable drive element spaced from said punch for actuating said punch and movable toward and away from said punch, a drive spring urging said driver element toward said punch, an impact transfer member positioned between said driver element and said punch and movable toward and away from said punch for transferring driving power from said driver element to said punch, said punch normally being free to move between said circular cutting edge and said transfer member an amount sufiicient to allow said continuously moving material to pass between said die surface and said punch, and means engageable with said driver for retracting said driver against the force of said drive spring and then releasing said driver element to be driven by said spring against said transfer member, whereby to cause said transfer member to drive said punch into temporary engagement with said cutting edge.

2. An improved perforator for making holes in heatsealable material, said perforator comprising a die having a hole therein forming a sharp circular cutting edge in the surface of said die, a punch movable toward and away from said die and having a spherical surface portion engageable with said circular cutting edge, the radius of curvature of said spherical surface portion being larger than the radius of said circular cutting edge, an elongated plunger for actuating said punch and reciprocable toward and away from said punch, a drive spring urging said plunger toward said punch, an impact transfer member positioned between said plunger and said punch and movable toward and away from said punch for transferring driving power from said plunger to said punch, said punch normally being free to move between said circular cutting edge and said transfer member an amount sufficient to allow said material to pass between said die and said punch, and actuator means engageable with said plunger for retracting said plunger against the force of said spring and releasing said plunger to be driven by said drive spring against said transfer member, whereby to cause said transfer member to drive said punch into temporary engagement with said cutting edge, said actuator means comprising rotatable cam means engagea'ble with said plunger and bevelled to retract said plunger upon engagement of said cam and said plunger, said cam means terminating abruptly and abruptly releasing said plunger.

3. An improved perforator for making holes in a continuously moving web of packaging material, said perforator comprising a die having a fiat surface over which said material passes, said surface having a hole therein forming a sharp circular cutting edge in said surface, a punch movable toward and away from said die and comprising a sleeve fixed in position in axial alignment with said die hole and spaced from said die surface and a ball slidable in said sleeve and engageable with said circular cutting edge, the radius of said ball being larger than the radius of said circular cutting edge, a reciprocable driver element spaced from said sleeve for actuating said punch and movable toward and away from said sleeve, a drive spring urging said driver element toward said sleeve, an

'impact transfer member positioned between said driver member, whereby to cause said transfer member to drive said ball into temporary engagement with said cutting edge.

4. An improved perforator for making holes in a continuously moving web of heat-scalable material, said perforator comprising a die having a hole therein forming a sharp circular cutting edge in the surface of said die, a punch movable toward and away from said die and having a spherical surface portion engageable with said *circular cutting edge, the radius of curvature of said spherical surface portion being larger than the radius of said circular cutting edge, a reciprocable driver spaced from said punch for actuating 'said punch and :movable toward and away from said punch, a drive spring urging said driver toward said punch, an impact transfer member positioned between said driver and said punch and movable toward and away from said punch for transferring driving power from said driver to said punch, a return spring urging said transfer member in a direction away from said punch and toward said driver whereby said punch normally is free to move between said circular cutting edge and said transfer member an amount sufiicient to allow said material to pass between said die surface and said punch, and actuator means engageable with said driver for retracting said driver against the force of said drive spring and releasing said driver to be driven by said drive spring against said transfer member, whereby to cause said transfer member to drive said punch into temporary engagement with said cutting edge, said actuator means comprising a rotatable disc adjacent to said driver, a cam carried by said disc, and a lug projecting from said driver into the path of rotation of said cam, said cam and said lug having complimentary engageable surfaces bevelled to cause retraction of said driver upon engagement of said cam and said lug, at least one of said engageable surfaces terminating abruptly and abruptly releasing said driver after retraction.

5. An improved perforator for making holes in a continuously moving web of packaging material and comprising a die having a hole therein forming a sharp circular cutting edge in the surface of said die, a punch movable toward and away from said die and having a spherical surface portion engageable with said circular cutting edge, the radius of curvature of said spherical surface portion being larger than the radius of said circular cutting edge, an elongated plunger movable toward and away from said punch for actuating said punch, a drive spring urging said plunger toward said punch, an impact transfor member positioned between said plunger and said punch and comprising a rod movable toward and away from said punch and a sleeve guiding said rod, a return spring urging said rod toward said plunger whereby said punch normally is free to move between said rod and said circular cutting edge an amount suflicient to allow said material to pass between said die surface and said punch, and actuator means engageable with said plunger for retracting said plunger against the force of said drive spring and releasing said plunger to be driven by said drive spring against said rod, whereby to cause said rod to drive said punch into temporary engagement with said cutting edge, said actuator means comprising rotatable cam means engageable with co-operating cam means on 6 said plunger, at least one of said cam means being bevelled to retract said plunger upon engagement of said cam means and said cam and lug abruptly releasing said plunger after retraction.

6. An improved perforator for making holes in a continuously moving web of packaging material, said perforator comprising a stationary die having avflat surface over which to pass the material to be perforated, said fiat surface havinga circular opening therein forming at the periphery of said opening a sharp circular cutting edge, a punch disposed opposite said opening and comprising a guide sleeve axially aligned with said opening and a ball in said sleeve movable into and out of engagement with plunger .for driving said rod againstsaid ball and movable toward and away from'said rod, a :second spring urging said plunger towardsaid rod, an tactuatorfor said plunger comprising a rotatable shaft adjacent to said plunger, a discxkeyed to :said shaft, a plurality of cam means fixed towsaid disc and individuallyengageable with'said plunger upon rotation ofsaid shaft to retract said plunger against the force of said second spring and then abruptly releasing said plunger to be driven toward said rod by said second spring.

7. An improved perforator for making holes in a continuously moving web of heat-scalable material, said perforator comprising a stationary die member having a flat surface over which to pass the material to be perforated, said fiat surface having a circular opening therein extending through said die member and forming at the periphery of said opening a sharp-edged cutting aperture in said surface, a punch element disposed opposite said opening and movable toward and away from said aperture along a line normal to said die surface, said punch element having a spherical surface portion engageable with said periphery of said opening, and means for driving said punch element into contact with said periphery of saido-pening, said means comprising a retractable element movable toward and away from said punch element along a line which is an extension of said first-named line, a spring normally urging said retractable element toward said punch element, means engageable with said retractable element for retracting said retractable element against the force of said spring and releasing said retractable element to be driven toward said punch element by said drive spring, and means engageable with said punch element for transmitting the driving force of said drive spring from said retractable element to said punch element whereby to drive said punch element into engagement with said periphery of said opening.

8. An improved perforator for making holes in a continuously moving web of packaging material, said perforator comprising a die having a flat surface over which said material passes, said surface having a hole therein forming a sharp circular cutting edge in said surface, a punch movable toward and away from said die and comprising a sleeve fixed in position in axial alignment with said die hole and spaced from said die surface and a ball slidable in said sleeve and engageable with said circular cutting edge, the radius of said ball being larger than the radius of said circular cutting edge, an elongated plunger axially aligned with said sleeve and reciprocable toward and away from said sleeve, a drive spring urging said plunger toward said sleeve, means associated with said spring for varying the effective force of said drive spring acting on said plunger, an impact transfer member positioned between said plunger and said punch and comprising a rod slidable in said sleeve toward and away from said ball for transferring driving power from said plunger to said ball, a return spring urging said rod away from said ball and toward said plunger whereby said ball normally is free to move in said sleeve between said circular cutting edge and the end of said rod an amount sufficient to allow said continuously moving web of material to pass between said die surface and said punch, and actuator means engageable with said plunger for retracting said plunger against the force of said drive spring and releasing said plunger to be driven by said drive spring against said transfer member, whereby to cause said transfer member to drive said ball into temporary engagement with said cutting edge, said actuator means comprising a rotatable disc adjacent to said plunger, a cam carried by said disc, and a lug projecting from said plunger into the path of rotation of said cam, said cam and said lug having complementary engageable surfaces bevelled to cause retraction of said plunger by said cam upon engagement of said cam and said lug, said cam and lug abruptly releasing said plunger after retraction.

9. An improved spring-actuated perforator for making holes in a continuously moving web of packaging material including a die having a smooth surface adjacent which 20 mass, said punch moving freely along said guide means toward and away from said die opening, an impact transfer member of larger mass than said punch and being movable toward and away from said punch for moving said punch toward said die opening, return spring means urging said impact transfer member away from said punch, a stop engaging said impact transfer member and stopping said transfer member in a position for allowing said web to pass freely between said die opening and said punch, a driver element of larger mass than said impact transfer member, drive spring means urging said driver element toward said impact transfer member, and retracting and quick-release mechanism for engaging said driver element and retracting it against the force of said drive spring means and then releasing said driver element when in retracted position.

References Cited in the file of this patent UNITED STATES PATENTS 1,305,766 Bullard June 3, 1919 1,417,867 Streibel May 30, 1922 FOREIGN PATENTS 10,436 Great Britain Apr. 28, 1914

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