US3735557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Machine for wrapping palletized loads in heat shrinkable plastic film
Assignee: Possis Machine Corp
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Filing: 1971-08-16
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Granted: 1973-05-29
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Expires: 1991-08-16
Abstract
Abstract A machine for forming bags of gussetted flat heat sealable web stock, opening the formed bags and drawing them down over palletized loads preparatory to conveying the same into an oven where the bags shrink into intimate contact with the load. The bags are opened by suction cup and claw assemblies mounted on the ends of arms that project from hinged carrier frames between which the palletized load is placed to be enwrapped. The frames swing towards and from one another, and in their innermost positions bring the suction cups into contact with the side panels of the pendently hanging web. This causes the suction cups to attach themselves to the side panels, and that attachment brings about initial retraction of the suction cups. With the side panels held by the suction cups, the claws are actuated to cause them to penetrate and grab the side panels. Outward swinging motion of the carrier frames and downward travel of the arms that carry the suction cup and claw assemblies opens the bag and draws it down over the load.
Inventors
- 👤 O Hoffarth
- 👤 T Schuette
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:52
CPC Classifications
B; B65; B65B; B65B9/00; B65B9/10; B65B9/13; B65B9/135
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
349 words
In a machine for wrapping a load presented to the machine on movable load supporting means, in plastic film wherein the film in the form of a flattened gussetted web is drawn from a roll thereof and fed along a defined path which includes a vertical stretch in which the web moves downward towards the load with its gussets closed and its side panels in close juxtaposition and pendently vertical, and which path passes through a cutoff station and a heat sealing station at which, respectively, a length of the leading portion of the vertical stretch of the web is severed from the rest of the web and overlying portions of the trailing end of the severed length are heat sealed to form at least a partially closed upper end for said severed length, said machine being characterized by improved means for opening the gussetted web and pulling it down over the load, and which improvement comprises: A. nip rolls located downstream from the cutoff and heat sealing stations by which the gussetted web is iteratively advanced and by which the trailing upper end portion of the severed length of web is held from dropping down onto the load until its bottom end has been opened; B. a plurality of suction cups, each operable to attach itself to a side panel of the web; C. movable mounting means mounting certain of said suction cups at each of the opposite sides of the pendent portion of the web, and operable to move the same inwardly towards the pendent portion of the web to positions at which the suction cups do attach themselves to the side panels of the web and outwardly to draw the side panels apart and in so doing coact with the nip rolls to hold the side panels against any substantial flatwise displacement, there being at least one pair of suction cups to engage each of the opposite side portions of each side panel; and D. movable claw means located between the suction cups of each pair thereof operable to penetrate and grasp the held side panels.
Claim 2
Dependent Claim
349 words
In a machine for wrapping a load presented to the machine on movable load supporting means, in plastic film wherein the film in the form of a flattened gussetted web is drawn from a roll thereof and fed along a defined path which includes a vertical stretch in which the web moves downward towards the load with its gussets closed and its side panels in close juxtaposition and pendently vertical, and which path passes through a cutoff station and a heat sealing station at which, respectively, a length of the leading portion of the vertical stretch of the web is severed from the rest of the web and overlying portions of the trailing end of the severed length are heat sealed to form at least a partially closed upper end for said severed length, said machine being characterized by improved means for opening the gussetted web and pulling it down over the load, and which improvement comprises: A. nip rolls located downstream from the cutoff and heat sealing stations by which the gussetted web is iteratively advanced and by which the trailing upper end portion of the severed length of web is held from dropping down onto the load until its bottom end has been opened; B. a plurality of suction cups, each operable to attach itself to a side panel of the web; C. movable mounting means mounting certain of said suction cups at each of the opposite sides of the pendent portion of the web, and operable to move the same inwardly towards the pendent portion of the web to positions at which the suction cups do attach themselves to the side panels of the web and outwardly to draw the side panels apart and in so doing coact with the nip rolls to hold the side panels against any substantial flatwise displacement, there being at least one pair of suction cups to engage each of the opposite side portions of each side panel; and D. movable claw means located between the suction cups of each pair thereof operable to penetrate and grasp the held side panels.
Claim 3
Dependent Claim
87 words
The machine of claim 1, wherein said movable mounting means mounts the claw means as well as the suction cups for inward movement towards and outward movement from said vertical stretch of the web in defined paths sufficiently above the load supporting means as to be above a load thereon, the suction cups and claw means when in their outer positions being horizontally spaced apart sufficiently to clear a load on the load supporting means and in their inner positions being contiguous to the pendent side panels.
Claim 4
Dependent Claim
59 words
The machine of claim 2, further characterized in that said movable mounting means further provides for vertical movement of the suction cups and claw means to draw the tubular web down around a load on the load supporting means; and means for actuating said movable mounting means to effect said defined movements of the suction cups and claw means.
Claim 5
Dependent Claim
97 words
The machine of claim 3, wherein said movable mounting means for the suction cups and the claw means comprises: A. an upright carrier frame at each of two opposite sides of the load supporting means; B. pivot means at the bottom end of each of said carrier frames, mounting the same for swinging motion about a horizontal axis towards and from said vertical stretch of the path of the web; and C. arm means on said upright carrier frames projecting inwardly therefrom and having the suction cups and the claw means mounted on the free ends thereof.
Claim 6
Dependent Claim
30 words
The machine of claim 4, wherein the suction cups are mounted on the arm means by collapsible bellows which, upon being collapsed, draw the suction cups towards the carrier frames.
Claim 7
Dependent Claim
92 words
The machine of claim 4, further characterized by: A. a pair of endless sprocket chaIns trained over spaced apart axially aligned upper and lower sprocket pinions at the upper and lower ends of each carrier frame; and B. cross bars attached to their ends to the same stretch of each of said endless sprocket chains, said arm means being mounted on the cross bars so that rotation in unison of one of the sprocket pinions for each chain moves the arm means up or down depending upon the direction of such rotation.
Claim 8
Dependent Claim
49 words
The machine of claim 6, wherein said crossbars hold the arm means so oriented when the pivoted carrier frames are in their innermost positions that the mouths of the suction cups have their edges lying in vertical planes and hence parallel to the pendent side panels of the web.
Claim 9
Dependent Claim
35 words
The machine of claim 6, wherein the mounting of the arm means on the crossbars provides for adjustment of the location of the arm means lengthwise of the crossbars to accommodate webs of different widths.
Claim 10
Dependent Claim
42 words
The machine of claim 8, wherein the length of the arm means is adjustable, to enable the distance the suction cups and claw means are spaced from the carrier frames to be coordinated with the girth of the load to be enwrapped.
Claim 11
Dependent Claim
88 words
The machine of claim 1, wherein the suction cups of each pair thereof are spaced horizontally, wherein the suction cups are mounted on the arm means by collapsible bellows which, upon being collapsed, draw the suction cups toward the carrier frames, whereby the stretch of the side panel between each pair of suction cups is pulled outwardly and the portion thereof directly above said stretch assumes a partially horizontal disposition, and wherein the claw means move with a downward motion to penetrate said portion of the side panel.
Claim 12
Dependent Claim
46 words
The machine of claim 10, wherein the claw means move with an outward as well as a downward motion, and further characterized by anvil means between each pair of the suction cups, and against which the claw means clamps the adjacent portion of the side panels.
Claim 13
Dependent Claim
31 words
The machine of claim 11, further characterized in that each claw means has a sharp claw projecting from a shoulder, the latter forming a clamping surface to coact with the anvil.
Claim 14
Dependent Claim
58 words
The machine of claim 1, wherein said web of gusseted tubular stock is in the form of a series of pre-made bags joined to one another by frangible connections, and further characterized by a pair of tear-off rolls beneath the nip rolls, operable to grip the web and coact with the nip rolls to tear the frangible connections.
Claim 15
Dependent Claim
24 words
The machine of claim 13, wherein said tear-off rolls have means to cause the frangible connections to be progressively torn along the length thereof.
Claim 16
Dependent Claim
45 words
The machine of claim 14, further characterized in that said means to effect progressive tearing of the frangible connections comprises: gripping pads on one of said tear-off rolls arranged helically thereon and adapted to successively clamp the web against the other of said tear-off rolls.
Claim 17
Dependent Claim
52 words
The machine of claim 1, further characterized by sensor means located to sense attachment of the claw means to the side edge portions of both side panels, and operable to effect stoppage of the machine in the event either side edge portion of either side panel is not held by claw means.
Claim 18
Dependent Claim
90 words
The machine of claim 4, wherein the cut-off station has cutoff means operable to sever the web downstream of the nip rolls; and further characterized by powered drive means; and motion transmitting means connecting said powered drive means with the nip rolls, the cutoff means and the carrier frames, to effect swinging motion of the latter to carry the suction cups and claw means towards and from said vertical stretch of the path of the web in timed relation with the functioning of the nip rolls and the cutoff means.
References Cited (Backward Citations)
US3621638A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |