Bag making machine

Claim 2

A machine for making bags of the type commonly called flats and squares, notion or millinery bags, comprising: a tube former for folding a flat bag material into the form of a continuous flat tube, a first perforator means located in advance of said former, a second perforator means located along the extent of said former at a point corresponding to said web having been folded over into tube form to a considerable extent but before completion of such folding, a tension applying means located after said former and being for applying a tension to said tube on opposite sides of a line of perforations thereacross made by said perforator means whereby rupture of said tube occurs along said line of perforations, said first and second perforator means each being arranged to perforate said web in a transverse direction along respective mutually exclusive extents of its width so as to form in combination a continuous line of perforations across the entire width of said web.

Claim 3

The machine of claim 1, said former comprising a former plate having an upwardly extending heel at its front end and an elongate portion extending therefrom in the direction of travel of said web, an opening in said elongate portion, said second perforator means comprising a perforator roller and an anvil roller rotatively mounted about respective axes above and below said plate and cooperating with each other through said opening, a first positive feed roller means located ahead of and in close proximity to said second perforator means and comprising an upper and lower feed roller means rotatively mounted about respective axes above and below said plate and cooperating with each other through a corresponding opening in said plate.

Claim 4

The machine of claim 2, said upper first feed roller means comprising two coaxially aligned and transversely spaced apart upper rollers located closely adjacent the lateral edges of said plate, the last mEntioned opening comprising an opening in said plate for each of said upper feed rollers, said upper feed rollers being engageable with said lower feed roller means through said opening.

Claim 5

The machine of claim 2, said second perforator means being aligned along the longitudinal middle axis of the machine said upper first feed rollers being symmetrically aligned on opposite sides of said longitudinal axis.

Claim 6

The machine of claim 1, said first perforator roller and a main anvil roller cooperatively associated with each other and mounted about mutually parallel axes on a common stand, said stand being adjustable transversely to the longitudinal direction of travel of said web through the machine.

Claim 7

The machine of claim 2, said first perforator means comprising a main perforator roller and anvil roller mounted about mutually parallel axes and cooperatively associated with each other for perforating said web, the perforator rollers of said first and second perforator means each comprising a rotary shaft having a toothed perforator blade mounted thereon for rotation therewith, means mounting said blade on said shaft whereby the pitch diameter of the blade teeth relative to a particular said shaft may be changed at will, the outermost arc of said teeth intersecting the circumferential arc of said anvil roller.

Claim 8

The machine of claim 6, said perforator rollers each comprising a blade holder removably mounted on each of said shafts for easy interchange with other analogous holders, a said blade being mounted in said holder to provide a particular pitch diameter of the blade teeth.

Claim 9

The machine of claim 6, said perforator and anvil rollers being parallelly displaceable relative to one another in order to accommodate different ones of said blades having different pitch diameters.

Claim 10

The machine of claim 6, the perforator blade on each said perforator roller being a flat blade which in end view lies in a plane which is nonradial relative to the rotational axis of the perforator roller and which forms an acute angle with a straight line interconnecting the axes of said perforator roller and the corresponding anvil roller at a point between the perforator roller axis and said outermost arc at the moment that the blade teeth first intersect the circumferential arc of the anvil roller.

Claim 11

The machine of claim 9, said angle being in the order of 15 to 45*.

Claim 12

The machine of claim 6, said main perforator roller comprising a plurality of coaxially aligned sleeves which are rotatively and axially adjustable relative to each other on said shaft, a blade holder removably mounted on each said sleeve, said holder being interchangeable on said sleeve with other analogous holders.

Claim 13

The machine of claim 6, wherein said main perforator roller and main anvil roller are drivingly interconnected by a gear on the main perforator roller interengaging a gear on the main anvil roller, one of said gears being removably mounted on its corresponding roller in order to permit interchange with other sized gears so as to compensate for a change in the pitch diameter of said blade teeth.

Claim 14

The machine of claim 1, said first perforator means comprising a main perforator and a main anvil roller mounted about mutually parallel axes for cooperation with each other to perforate said web, a slip roller mounted parallel to the main anvil roller and ahead thereof relative to the travel of said web through the machine, gear means drivingly interconnecting said slip roller with said main anvil roller.

Claim 15

The machine of claim 1, including a main cylinder rotatively mounted at one end of the machine for rotation in the direction of web travel through the machine, said cylinder being adapted to carry bag length portions of said tube along its circumferential surface past a tucker bar and to a bag receiving station at the outlet end of the machine, said tension applying means comprising a rotary pinch bar operatively associated with said cylinder so as to periodIcally provide an interface therebetween to grip said tube between said bar and cylinder and thereby advance said tube in said direction of travel, a tube restraining means located ahead of said cylinder and bar and being adapted to restrain said tube relative to the speed of advance imparted thereto by said cylinder and bar whereby a tensile force is imparted to said tube in the extent thereof between said restraining means and said bar and cylinder.

Claim 16

The machine of claim 14, said restraining means comprising a pinch roller assembly including an upper and lower pinch roller for gripping said tube therebetween and for advancing same towards said main cylinder at a speed lower than the speed imparted to said tube by said cylinder and pinch bar, control means for periodically separating said pinch rollers relative to each other to an extent sufficient for them to release the tube which is therebetween.

Claim 17

The machine of claim 14, further including a positive feed roller means for advancing said tube from said second perforator means towards said restraining means, said positive feed roller means being located at a distance from and ahead of said restraining means, control means to periodically cause said restraining means to successively grip and release said tube, the advance of said tube being restrained by such gripping relative to said main cylinder and relative to said feed rollers, said control means being timed to effect gripping of said tube by said restraining means for a period of time just prior to and during the aforementioned periodic gripping of said tube by said pinch bar whereby a slack develops in said tube in the longitudinal extent thereof between said feed rollers and said restraining means before said tube is gripped by said pinch bar.

Claim 18

The machine of claim 16, wherein said restraining means comprises an upper and a lower pinch roller for gripping said tube therebetween, and thereby advancing said tube from said feed rollers toward said main cylinder, said control means being adapted to periodically separate said pinch rollers from each other so as to release the tube therebetween and successively to bring said pinch rollers together so as to grip the tube therebetween, said pinch rollers being driven and being adapted to advance said tube during the aforementioned gripping thereof at a speed slower than the speed imparted thereto by said feed rollers.

Claim 19

The machine of claim 17, said feed rollers being driven at a speed so as to advance said tube at a slower speed than the speed of advance imparted thereto by the pinch bar and main cylinder.

Claim 20

The machine of claim 14, including a corner defining means mounted adjacent to said main cylinder between said restraining means and said pinch bar, said pinch bar being arranged relative to said main cylinder whereby an angle path for the tube is defined leading from said restraining means around said corner means and to the interface between said pinch bar and said main cylinder.

Claim 21

The machine of claim 19, wherein said corner means is a slip roller.

Claim 22

The machine of claim 14, wherein said pinch bar comprises a tube gripping surface which periodically passes adjacent to the surface of said main cylinder pursuant to rotation of said bar and thereby defines said interface, said tube gripping surface being spiraled relative to the axis of rotation of said main cylinder.

Claim 23

The machine of claim 21, said pinch bar and main cylinder being rotatively mounted about mutually parallel axes and said gripping surface on said bar being spiraled relative to the axis of said bar.

Claim 24

The machine of claim 14, wherein said pinch bar comprises a rotary shaft having a radially extending protrusion which is continuous along the shaft length and which defines an outer peripheral edge of limited circumferential extent, said edge periodically meeting the surface of said main cylinder to grip said tube therebetween.

Claim 25

The machine of claim 23, said edge being spiraled along the axial extent of said pinch bar shaft.

Claim 26

The machine of claim 23, wherein said pinch bar includes a cover of flexible material tightly fitted around the periphery of said pinch bar shaft and said peripheral edge, said cover being replaceably fitted on said shaft.

Claim 27

The machine of claim 16, including a driven belt means arranged to travel from said restraining means towards said main cylinder adjacent to the tube path defined between said restraining means and said cylinder, said belt means being adapted to slidingly engage a surface of the tube and thereby urge same towards said cylinder.

Claim 28

The machine of claim 26, said belt means including a belt which extends from the location of said positive feed rollers towards said main cylinder.

Claim 29

The machine of claim 26, said belt means extending along a portion of the surface of said main cylinder to a point beyond the location of said pinch bar, said belt means extending between said pinch bar and the surface of said main cylinder.

Claim 30

The machine of claim 28, said belt means being driven at a surface speed equal to that of said main cylinder.

Claim 31

A bag making machine of the type having a main cylinder assembly for receiving a flat tube of bag material along the outer circumferential surface of a rotary cylinder and tucker means cooperatively associated with said cylinder for forming a closed bottom end on said tube, said machine comprising a severing means for successively dividing said tube into preestablished bag lengths, said severing means including: a. a means for establishing a continuous line of weakness transversely along both layers of the tube width at successive locations along the length of said tube; b. a tube feed means for advancing the continuous tube with said lines of weakness therein towards said main cylinder at a first speed of advance; and c. a rotary pinch bar operatively associated with said main cylinder for periodically meeting same and gripping the tube thereagainst and thereby pulling it away from said feed means at a faster speed than said first speed whereby the tube portion along the main cylinder severs from the tube portion extending between said feed means and said main cylinder along a one of said lines of weakness, said pinch bar having a spirally extending surface along the axial extent thereof whereby as said bar rotates said surface meets the surface of said main cylinder progressively along the axial direction of said bar so that a said tube is correspondingly gripped between said surfaces progressively across its width.

Claim 32

A bag making machine of the type having a main cylinder assembly for receiving a flat tube of bag material along the outer circumferential surface of a rotary cylinder and tucker means cooperatively associated with said cylinder for forming a closed bottom end on said tube, said machine comprising a severing means for successively dividing said tube into preestablished bag lengths, said severing means including: a. a means for establishing a continuous line of weakness transversely along both layers of the tube width at successive locations along the length of said tube; b. a tube feed means for advancing the continuous tube with said lines of weakness therein towards said main cylinder at a first speed of advance; and c. a rotary pinch bar operatively associated with said main cylinder for periodically meeting same and gripping the tube thereagainst and thereby pulling it away from said feed means at a faster speed than said first speed whereby the tube portion along the main cylinder severs from the tube portion extending between said feed means and said main cylinder along a one of said lines of weakness, said pinch bar having a spirally extending surface along the axial extent thereof whereby as said bar rotates said surface meets the surface of said main cylinder progressively along the axial direction of said bar so that a said tube is correspondingly gripped between said surfaces progressively across its width.

Claim 33

The machine of claim 30, including a corner defining means along the tube path extending from said feed means to the point at which said pinch bar meets said cylinder, said feed means together with said corner means and said pinch bar defining an angled tube path whereby said pinch bar and cylinder exert a pulling force to a portion of the tube which extends from said pinch bar to said corner means and which is angled relative to a following portion of the tube which extends back from said corner means to said feed means.

Claim 34

A bag making machine of the type having a main cylinder assembly for receiving a flat tube of bag material along the outer circumferential surface of a rotary cylinder and tucker means cooperatively associated with said cylinder for forming a closed bottom end on said tube, said machine comprising a severing means for successively dividing said tube into preestablished bag lengths, said severing means including: a. a means for establishing a continuous line of weakness transversely along both layers of the tube width at successive locations along the length of said tube; b. a tube feed means for advancing the continuous tube with said lines of weakness therein towards said main cylinder at a first speed of advance; c. a rotary pinch bar operatively associated with said main cylinder for periodically meeting same and gripping the tube thereagainst and thereby pulling it away from said feed means at a faster speed than said first speed whereby the tube portion along said main cylinder severs from the tube portion extending between said feed means and said main cylinder along a one of said lines of weakness; d. wherein said feed means comprises a positive feed roller means for advancing said tube towards said main cylinder and a restraining means spaced from said feed roller means and located between same and said main cylinder, said restraining means being adapted to periodically restrain the travel of the tube relative to the pulling force imparted thereto by said pinch bar and main cylinder; and e. wherein said restraining means is also adapted to restrain the tube relative to the feed speed imparted thereto by said feed roller means, whereby a slack develops along the extent of said tube between said feed roller means and said restraining means.

Claim 35

A bag making machine of the type having a main cylinder assembly for receiving a flat tube of bag material along the outer circumferential surface of a rotary cylinder and tucker means cooperatively associated with said cylinder for forming a closed bottom end on said tube, said machine comprising a severing means for successively dividing said tube into preestablished bag lengths, said severing means including: a. a means for establishing a continuous line of weakness transversely along both layers of the tube width at successive locations along the length of said tube; b. a tube feed means for advancing the continuous tube with said lines of weakness therein towards said main cylinder at a first speed of advance; c. a rotary pinch bar operatively associated with said main cylinder for periodically meeting same and gripping the tube thereagainst and thereby pulling it away from said feed means at a faster speed than said first speed whereby the tube portion along said main cylinder severs from the tube portion extending between said feed means and said main cylinder along a one of said lines of weakness; d. wherein said feed means comprises a positive feed roller means for advancing said tube towards said main cylinder and a restraining means spaced from said feed roller means and located between same and said main cylinder, said restraining means being adapted to periodically restrain the travel of the tube relative to the pulling force imparted thereto by said pinch bar and main cylinder; and e. wherein said restraining means is also adapted to restrain the tube relative to the feed speed imparted thereto by said feed roller means, whereby a slack develops along the extent of said tube between said feed roller means and said restraining means.

Claim 36

The machine of claim 32, wherein said restraining means is arranged to exert the aforementioned restraint upon said tube for a period of time commencing prior to said pinch bar meeting said main cylinder to grip the tube thereagainst until after the pinch bar has rotated to a point whereby it releases the tube relative to said cylinder, said restraining means being arranged to then release said restraint upon said tube, and including slip feed means between said feed roller means and said main cylinder for advancing the tube towards the main cylinder at a speed higher than the feed speed of said feed roller means.

Claim 37

A bag making machine comprising a means for advancing a bag material along a path of travel from the inlet to the outlet end of said machine, said means comprising in succession from said inlet end to said outlet end: a main perforator roller and associated anvil roller; a tube former plate; a first positive feed roller means located along the length of said tube former plate; a final perforator roller and associated anvil roller located along the length of said tube former plate immediately behind said first feed roller means; a second positive feed roller means; a pinch roller means; a main cylinder and a pinch bar operatively associated therewith for gripping the bag material therebetween; said main perforator and anvil rollers being adapted to transversely perforate a portion of the width of the bag material; said first feed roller means being adapted to draw the bag material off a freely rotatable supply roll, over said main anvil roller, and along a portion of said former plate; said final perforator roller and anvil roller being adapted to transversely perforate the remaining portion of the width of said material so as to form a continuous line of perforations across the entire width of said material; said second feed roller means being adapted to draw the bag material along said plate from said first feed roller means and to advance it towards said pinch roller means at the same speed as said first feed roller means advances said material; said pinch roller means being adapted to periodically engage said bag material and advance same at a slower speed than said second feed roller means; said main cylinder and pinch bar being adapted to periodically grip the bag material therebetween and advance it at a faster speed than either said pinch rollers or said second feed rollers; and including control means to cause said pinch rollers to successively engage and release said bag material.

Claim 38

A bag making machine comprising a means for advancing a bag material along a path of travel from the inlet to the outlet end of said machine, said means comprising in succession from said inlet end to said outlet end: a main perforator roller and associated anvil roller; a tube former plate; a first positive feed roller means located along the length of said tube former plate; a final perforator roller and associated anvil roller located along the length of said tube former plate immediately behind said first feed roller means; a second positive feed roller means; a pinch roller means; a main cylinder and a pinch bar operatively associated therewith for gripping the bag material therebetween; said main perforator and anvil rollers being adapted to transversely perforate a portion of the width of the bag material; said first feed roller means being adapted to draw the bag material off a freely rotatable supply roll, over said main anvil roller, and along a portion of said former plate; said final perforator roller and anvil roller being adapted to transversely perforate the remaining portion of the width of said material so as to form a continuous line of perforations across the entire width of said material; said second feed roller means being adapted to draw the bag material along said plate from said first feed roller means and to advance it towards said pinch roller means at the same speed as said first feed roller means advances said material; said pinch roller means being adapted to periodically engage said bag material and advance same at a slower speed than said second feed roller means; said main cylinder and pinch bar being adapted to periodically grip the bag material therebetween and advance it at a faster speed than either said pinch rollers or said second feed rollers; and including control means to cause said pinch rollers to successively engage and release said bag material.

Claim 39

The machine of claim 34, including a slip roller ahead of said main anvil roller, said slip roller being positively driven by said anvil roller.

Claim 40

The machine of claim 34, including a drive arrangement wherein said main cylinder is rigidly drivingly interconnected with said pinch bar, with said first and second feed rollers and said pinch roller means, and with said main and final perforator rollers whereby the rotative speed of said main cylinder determines the rotative speed of the aforementioned drivingly interconnected components with no slippage of either of the components being possible rElative to said main cylinder.

Claim 41

The machine of claim 36, wherein said main cylinder is drivingly interconnected with the first and second feed rollers and the pinch roller means through a first positive transmission train and with the main and final perforator rollers through a second transmission train which is independent of the first train, whereby a change in said first train can be effected to change the rotative speeds of said first and second feed rollers and of said pinch roller means relative to said main cylinder without changing the rotative speeds of said main and final perforator rollers relative to said main cylinder.

Claim 42

The machine of claim 37, wherein the driven components in each of said trains are each rigidly drivingly interconnected whereby the rotative speed of any one component in any train necessarily is fixed relative to the rotative speed of all other components in that same train.

Claim 43

The machine of claim 38, wherein said first train comprises a main change gear replaceably mounted between said main cylinder and one of the components of said first train, whereby replacement of said change gear by one of different size automatically changes the rotative speeds of all first train components relative to said main cylinder without disturbing the speed relationship between any two first train components.

Claim 44

The machine of claim 39, wherein said main and final perforator rollers carry perforator blades the pitch diameter of which is changeable, each perforator and anvil roller being so mounted whereby the distance therebetween is adjustable in accordance with a change in said pitch diameter.

Claim 45

The machine of claim 40, including a second change gear replaceably mounted in driving relationship between said main perforator roller and said main anvil roller whereby the rotative speed of said main anvil roller may be changed in accordance with a change in said pitch diameter.

Claim 46

The machine of claim 40, wherein said final anvil roller is free running.

Claim 47

The machine of claim 41, wherein said main anvil roller is drivingly connected with said final anvil roller whereby a changing of said second change gear automatically changes the rotative speed of both anvil rollers without altering the rotative speed relationship therebetween.

Claim 48

The machine of claim 37, said first and second feed rollers comprising respective powered lower rollers and corresponding upper rollers which are geared to the lower rollers, said upper rollers being slightly larger in diameter than the corresponding lower rollers.

Claim 49

The machine of claim 37, wherein said pinch roller means comprises an upper and a lower pinch roller, a gear integral with each of these last mentioned rollers, the gear on one engaging the gear on the other, said pinch rollers being parallelly reciprocable relative to each other to a maximum extent which is considerably less than the depth of the teeth on said pinch roller gears.

Claim 50

The machine of claim 45, including a spring means urging said pinch rollers apart and a driven cam which periodically urges said pinch rollers towards each other.