US2097183A - Bag making machinery - Google Patents

Description

@ct 1 aw. FRENCH BAG MAKING MACHINERY Filed May'lS, 1936 2 Sheets-Sheet 1 IN VEN 1'02 N Fee-N W 2 Patented Oct. 26, 1937 UNITED. STATES 2,097,183 4 BAG MAKING MACHINERY Gordon William French, Bristol, England Application May 15, 1936, Serial No. 79,851

. In Great Britain May 21, 1935 8 Claims.

' This invention comprises improvements in and relating to machinery for making bags from paper, transparent or translucent viscose materials or the like.

In the present method of cutting tubular sheet material into predetermined lengths for the purpose of making bags and the like it is customary to form' the sheet material into flattened tubular form by feeding it round a former plate, located between the two axes of feeding rollers, the bottom roller being continuous, and the top roller consisting of two separate portions or treads mounted on a shaft, the plate having a restricted or neck portion to clear these treads. Sheet material fed over said plate is gripped between the top treads and bottom roller and has two edges imparted to it. The end of the former or guide plate from which the sheet material passes is shaped to act as a cutter plate, for example by being bevelled and, serrated, and slightly in rear of and narrowly spaced upon this cutting edge is what is known as a breaker plate, also having a serrated shearing edge, the arrangement being that what is known as a heater arm is moved across the plane of travel of the sheet material near to the shearing edge of the former or guide plate so as to break or tear the tubular sheet material along the two shearing edges of the said plates, which, being set one in advance of the other, imparts a stepped severance to the flattened tube of material.

This method of severance, although satisfactory for paper, is quite unsuitable for transparent viscose materials of the type known by the registered trade name Cellophane or the like, as the act of striking off the material against the serrated plates produces splits and cracks in the material; Theobject of the present invention is to providemeans for effecting a stepped severance of the flattened tube of material without producing the serrated and torn-edges associated with the use of a beater arm.

According to this invention the opposite sides of the flattened tube of paper, transparent or translucent viscose or other suitable material are each severed separately by individual knives or cutting blades adapted each to cut through.

the material at the required position to provide a severance of the flattened tube of material.

A practical embodiment of this invention can be summarized as consisting in the provision of a pair of cutting knives, one located above and one below the track of the tubular sheet material, means for moving said knives towards and away .from the opposite sides of'the tubular sheet material to individually shear opposite sides of the sheet material and means moving the cutting edges of said knives substantially synchronously .with and in the direction. of movement of the sheet material immediately succeeding the shearing operations.

One knife or cutting blade may be suitably shaped to provide an arcuate V shape or other form of cut in one side of the flattened tube. The knives or cutting blades preferably have a motion imparted to them in the same direction as the movement of the flattened tube of material during the actual cutting operation in addition to a-motion substantially transverse to the direction of movement of the flattened tube ofmaterial which effects the actual severance.

Each of the knives or cutting blades is so mounted and operated that it will rotate about an axis so that during-its rotation the path of the outer end of each knife or cutting blade will intersect the path of travel of one of the two sides of the tube of sheet material. The direction of rotation of the two knives or cutting blades is such that during the period of intersection with the two sides of the tube of sheet material and whilst the severance of this sheet material is beingv effected the knives or cutting blades will travel in the same direction as the sheet material and the rate of rotation of the cutters will be so arranged that the cutting edges of the knives or cutting blades will move at approximately the same rate as the sheet material upon which they are operating.

- In a preferred form of this invention two knives or cutting blades may be each mounted to rotate about an axis and these knives or cutting blades are mounted on. opposite sides of the tubular sheet of material and are arranged to rotate in opposite directions to each other and are so positioned that each knife or blade will intersect with' and cause a severance of one side of the sheet of tubular material and will at the point of intersection be travelling in the same direction and approximately at the samespeed as the sheet of tubular material upon which they operate. The axis of revolution of one knife or cutting blade is preferably off-set from the axis of revolution of the other knife or cutting blade by an amount approximately equal to the step to be produced in the severance of the tube of sheet material. 50 The knives or cutting blades are preferably located so that the point at which the knives or blades commence the severance of the sheet material is close to the end of the former plate- In orderthat my invention may be clearly Fig. 4 is a detail side elevation view showing an alternative form of mechanism for operating the cutters, and

Fig. 5 is a detail end elevation view of a suitable form of mechanism for adjusting the rate of travel of the cutting edges of the knives to cor-- respond with the rate of travel of the sheet material to enable bags of varying depth to be produced on one machine.

Referring to the drawings the tubular sheet materialto be cut into lengths is indicated by the reference numeral and is fed flattened sleeve fashion over a former plate 2 of H configuration in plan sons to produce a central neck to enable the sheet materialto be gripped between .a pair of upper rollers 3 and a lower cylinder or roll 4 disposed beneath the former plate 2. A pair of steadying rolls 5 bear against the sheet material between the front or cutting end of the former plate 2 and the feed rolls 3 and 4 to maintain the sheet material in close contact with the former plate immediately before reaching the cutting stage. t

The cutters comprise an upper knife 6 and a lower knife I, the ends of the upper knife. 8 conveniently being bowed as at-Sd (see Fig. 3) to form the corners of a narrow flap adapted to be folded over the edge produced by the knife I to effect a closure of each bag.

A pair of draw-off rolls 8 andvfl, upper and lower respectively,- are arranged in front of the cutting stage adapted to receive between them the leading edges of the successively severed lengths of sheet material and to draw them and deliver them to a suitable stacking zone. These rolls 8 and 9 serve to exert the requisite tension on the material as it is about to be out, this tension being released considerably during the predominating portion of the feeding stage of each severed strip. For this purpose the upper roll is for a short portion of its circumference slightly;

increased in diameter to provide a projection l which bears against the sheet material immediately preceding and during the cutting stage, consequently the sheet material is momentarily placed under increased tension as it leaves the former plate 2 during'the cutting stage.

The pressure of the roller 8 upon the sheet material can be regulated by a pair of screws engaging bearing blocks |2 supporting the ends of the shaft of the roller and arranged in guides it formed on a machine frame M, coiled compression springs I yieldingly opposing the ad-,-

justment of the blocks l2 in well known manner.

The cutting edges of the knives or blades C and I may be either continuous or serrated or undulating in form. In order to provide the maximum support for the material during severanee the former plate 2 may be extended into or beyond the path swept out by the cutting blades.

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mounted upon a suitable rotary holder supported in bearings and adapted to rotate therein in the required direction and at the desired speed. The knives or cutting blades are so mounted in these holders that their outer or cutting edges rotate about circular pathso (indicated by the dotted line 61) and 'lb) so that they will intersect with one side of the tube of sheet material but not with the other side. The knives or cutting blades are arranged so that at the first point of contact with the tube of sheet material the cutting edges will be presented to this material approximately at right angles to the surface of the material'upon which they will act to effect a severance thereof as shown in Fig. 2. For this purpose the blades may conveniently be mounted on flats formed on shafts 6a and la so that they lie tangentiallyto a circle concentric with the axis of rotation and this circle may in some cases be of a radius approximately equal to one half of the radius about which the cutting edge rotates. This arrangement of the knives or cutting blades is intended to present the cutting edges thereof to the material to be severed so that during the act of severance the knives or cutting blades penetrate the material with amotion approximately at right angles to the plane of the material and at the-same time follow the forward motion of the material.

Suitable means are provided whereby bags of different depth may be cut on the same machine by varying the rate'of feed of the sheet material. At the same time the speed of the knives at the moment of impact with the sheet material must approximate to the speed of the material, consequently means is provided whereby the peripheral speed of the cutting edges of the knives can be uniform or can be adjustable to various degrees of non-uniformity. One method of effecting this desideratum is shown in Figs. 1 and 2 in which the shafts 8 and rotating on fixed axes are geared together by gear wheels 6c and I0 so that they travel at the same speed. The shaft 6a which is supported at both ends in bearings (one of which is indicated in Fig. 5) has radiating relatively fixedly from one .end a pin l6 which acts as a crank and slidable thereon is acollar ll located in a forked bracket l8 extending unilaterally from a disc I! which is fixed on the shaft 2| of a gear wheel 20. This shaft 2| is carried in a bearing at the upper and free end of an arm 22 radiating from and adjustable about the axis of a shaft 23 carrying a gear wheel 24 with which meshes the beforementioned gear wheel 20.

The adjustment of the arm 22 is efiected by a set screw 25 threaded through a boss 26 at the free end of a bracket 2lextending' from a fixed pedestal 28 carrying the bearing for the shaft 23. The upper end of this pedestal has passed through it a bolt .29 which also passes through an arcuate slot 30 in a lug 22a formed on the adjustable arm 22 whereby the latter may be secured in selected position.

When the knife shaft 60 is co-axial with the shaft 2| its rate of revolution is uniformbut if the arm 22 is adjusted so as to displace the axis of the shaft 2| relatively to the axis of the knife shaft to the collar I! will slide along the pin l6 during rotation of the disc |I resulting in the rate of revolution of the shaft 4 being variable for each complete revolution, its maximum speed being when the collar I1 is furthest from theaxis of the shaft 60.

By meansof the foregoing. the mean speed of the shafts 6a and leg can be infinitely varied to enable the machine to be set to cut variable lengths of bags, whilst at the same time a constant relationship of rate; of feed of the sheet material and speed of knives during the cutting stages can be maintained In conjunction with this arrangement the roller 8 is mounted so that it can be removed and replaced with a roller having a diameter and dimension of projection l0 appropriate to the requirements of the setting of the machine for the desired size of bag.

An alternative mechanism for operating the knives 6 and I is shown in Fig. 4 in which each knife or blade is mounted in a suitable holder 3| which is supported parallel link fashion by apair of cranks 32 and 33 in such a manner that when the cranks are turned about their axes the appropriate cutting knife or blade will be caused to rotate about a circular path indicated by the dotted line 34 whilst maintaining the cutting edges of the blades presented toward the opposite walls of the flattened tube of material. The two knives or blades are arranged uponopposite sides of the former plate and the path of travel of the cutting edges of the knives or blades is such that during their movement they will intersect the path of travel of the respective walls of the flattened tube of material I whilst the knives or blades are travelling in the same direction and at approximately the same speed.

The curved path of movement of the knives or blades will cause their edges to effect the cutting or severing operation whilst they are moving in the same direction as the flattened tube of material, and when the cutting operation has been effected the cutting edge of the knife or blade will be withdrawn and the continuation of its rotary movement will bring it backto its original position to efiect the next cutting operation after the desired lengthv of tubular material has been fed over the end of the former plate. Any other suitable form of mechanical motion may be em ployed to impart to the knives or blades the combined reciprocating motion in a direction substantiaily at right angles to the direction of travel of the tube of flattened material and also in a direction and at a speed corresponding substantially with the direction and rate of movement of the tube of flattened material during the actual cutting operation. Ii desired the position of the two knives or blades may be adjustable relatively to each other so as to vary the distance between the cut or severed edges of, the' two walls of the flattened tube of material.

; Interchangeable knives or blades may be pro- The arrangements described above comprise a simple construction and application of my invention'and forms anefilcient, practical, and cheap method and means for eiiecting the separate severance of the two sides of a tube of sheet material and also enables a stepped severance of the material to be effected. Ii desired'the position of the axis of rotation of one or both cutters relatively to the other or to the former plate may be adjustable.

I claim:-

1. In a paper bag making machine in which tubular sheet material is fed in a substantially flat condition over a former to a cutting zone forcutting it into lengths, the provision of a pair of cutting members one of which is adapted to one the otherside, means for rotating the cutting edgesof said knives in circular paths one above and one below the track of the sheet material, said track being substantially tangential with both of said circular paths and in a direction complementary to the direction of rotation of said-cutting edges, said means comprising parallel link motion devices supporting said cutting members and adapted to impart movement to the cutting edges simultaneously towards opposite sides of the sheet material in circular paths in opposite directions and complementary to the direction of travel .of the sheet material.

2. In a paper or likebag making machine, a former plate, means for feeding tubular sheetmaterial along said former plate, a pair of cut-' ters located one above and one below and in juxtaposition to one end of said former plate, means for drawing oil the sheet material from said former, and means moving said cutters substantially simultaneously against opposite sides of said tubular sheet material whereby the cutters individually sever opposite sides of the tubular sheet material, and means effecting variations in v the shearing intervals in' relation to a predetermined rateof feed of the sheet material, said latter means comprising a shaft rotatable-on a material along said former plate, a pair of cutters located one above and one below and in juxtaposition to one end of said'former plate, means for drawing oil the sheet material from said former, means moving said cutters substantially simultaneously against opposite sides of said tubular sheet material whereby the cutters individually sever opposite sides of the tubularsheet material, and means efiecting variations in the shearingintervals in relation to a predetermined rate of feed of the sheet material, and means momentarily increasing the tension of the tubular sheet material during the engagement of the knives or cutting members with opposed sides of the sheet material, said latter means comprising a draw-oil roll and another roll between which is gripped the sheet material after passing over the former plate or through the cutting zone,

said draw-0d roll being formed with a portion of its periphery slightly greater in diameter than the remainder of its periphery adapted to engage with the sheet material immediately in advance or and during the cutting stage.

i. In a paper or like bag making machine, a former plate, means for feeding tubular sheet material along said former plate, a pair of cutters located one above and one below and in juxtaposition to one end of said former plate, means for drawing oil the sheet material from said former, means moving said cutters substantially simultaneously'against opposite sides of said tubular sheet material whereby the cutters individually sever opposite sides of the tubular sheet material, means effecting variations in the shearing intervals in relation to a predetermined rate of. feed of the sheet material, means effecting a rate of movementof the cutting edges during the cutting stage which is constant in relation to the predetermined rate of feed of the sheet material,

and means momentarily increasingthe tension oi the tubular sheet material during the engagement of the knives or cutting members with opposed sides of the sheet material, said latter means comprising a draw-oi! roll and another roll between which ls gripp d the sheet material after passing over the former plate or through the cutting zone, said draw-oi! roll being formed with a cutting it into lengths, the provision of a pair of cutting members one of which is adapted to shear one side of the tubular sheet material and one the other side, means for rotating the cutting edges of said knives in circular paths one above .and one below the track of the sheet material,

said track being substantially tangential with both of said circular paths and in a direction complementary to the direction of rotation of said cutting edges, means for supporting the materialwith its two sides spaced apart at the cutting zone for an appreciable distance on at least one side of the path of the cutting edge of each cutting member, the movement of the cutting edges of the cutting members in the direction of movement of the material being substantially equivalent to the speed of travel of the material during the actual cutting operation and means. for applying additional tension on the material to hold it taut whilst the chtting members are severing the material.

6. In a paper bag making machine in which tubular sheet material is fed in a substantially flat condition over a former to a cutting zone for cutting it into lengths, the provision of a pair of 7 cutting members one of which is adapted to shear one side of the tubular sheet material andone the other side, means forrotating the cutting edges of said knives in circular paths one above and one below the track oi. the sheet material, said track being substantially tangential with bc-th of said circular paths and in a direction complementary to the direction of rotation 01' said cutting edges, means {or supporting the material with its two sides spaced apart at the cutting zone for an appreciable distance on at least one side of the path of the cutting edge of each cutting member, the movement of the cutting edges of the cutting members in the direction of movement of the material being substantially. equivalent to the speed of travel of the material during the actual cutting operation, and means momentarily increasing the tension of the tubular sheet material during the engagement of the knives or cutting members with opposed sides of the sheet material, said latter means comprising a draw-oil roll and another roll between which is gripped the sheet material after passing over the-former plate or through the cutting zone, said draw-oil roll being formed with a portion 0! its periphery slightly greater in diameter than the remainder of its periphery adapted to engage with the sheet material immediately in advanc of and during the cutting stage.

'1. In a paper bag making machine in which tubular sheet material is fed in a substantially flat condition over a former to a 'cutting zone for cutting it into lengths, the provision of a pair of cutting members one of which is adapted to shear one side of the tubular sheet material and one the other side, means for rotating the cuttingsedges 01'- said knives in circular paths one above and one below the track of the sheet material, ,said track being substantially tangential with both of said circular paths and in a direction complementary to the direction of rotation of said cutting edges, said last mentioned means including a driven gear wheel, a pinion in mesh with said gear wheel, means to adjust the axis of the pinion around the axis of the gear wheel, a

spindle connected to the cutting members for driving said members, and a sliding and pivoting connection between the spindle and said pinion.

8. In a paper bag making machine in which tubular sheetmaterial is fed in a substantially flat condition over a former to a cutting zone for cutting it into lengths, the provision of a pair of cutting members one of which is adapted to shear one side of the tubular sheetmaterial and one the other side at the cutting zone, a fixed former the front edge of which is spaced 9. short distance rearwardly of the cutting zone so that the sides of the material are held apart at the cutting zone by the former in the absence of any element between the sides at the cutting zone, means for rotating the cutting edges of said knives in circular paths one above and one below the track oi the sheet material, said track being substan-

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