Apparatus for wrapping articles

Claim 2

In an apparatus for wrapping articles in heat sealable sheet material as they move along an article path including upper and lower endless jaw conveyor means respectively having at least one upper and one lower jaw assembly extending generally horizontally crosswise of the article path, said upper and lower endless conveyor means respectively having generally horizontal lower and upper sections thereof extending forwardly along the article path in a sealing run in which one upper And one lower jaw assembly move in an opposed pair along the sealing run, means for supporting end sections of upper and lower webs respectively above and below the article path, the ends of which webs have previously been joined to form a curtain of the material extending crosswise of the article path adjacent the inlet end of said sealing run, means for advancing an article along the article path into the curtain to draw the curtain along the top and bottom of the article and to position the article in front of an opposed pair of said jaw assemblies as they move toward the inlet end of said sealing run, the improvement wherein said lower jaw assembly includes a pair of lower clamping jaw members extending crosswise of the article path and spaced apart in a direction lengthwise of the article path to define a jaw opening therebetween, means for guiding said upper and lower jaw assemblies as they move along the sealing run with an upper jaw assembly clamping overlapping portions of the upper and lower webs to the pair of lower clamping jaw members on a lower jaw assembly, a generally horizontal heat sealing and cutting member extending crosswise of said article path and mounted for movement in a closed loop course extending generally tangent to said upper section of said lower conveyor means in a zone intermediate the ends of said sealing run, and means for driving said sealing and cutting member in timed relation with said lower conveyor means along said closed loop course sequentially into the jaw opening in said lower jaw assembly as it moves past said intermediate zone to sever and seal overlapping portions of the upper and lower webs at opposite sides of the severance and then out of said lower jaw opening before the upper and lower jaw assemblies reach the end of the sealing run to allow the sealed webs to cool.

Claim 3

An apparatus for wrapping articles according to claim 1 wherein said heat sealing and cutting member is rotatably supported for movement in a circular path generally tangent to said sealing run.

Claim 4

An apparatus for wrapping articles according to claim 1 wherein said heat sealing and cutting member is rotatably supported on generally horizontal shaft means extending crosswise of said article path, means supporting said shaft means for limited vertical shifting movement, and means yieldably biasing said shaft means upwardly to yieldably urge said heat sealing and cutting member to a level slightly above said pair of clamping jaws on the lower jaw assembly.

Claim 5

An apparatus for wrapping articles according to claim 1 wherein said upper jaw assembly includes a face portion adapted to span said jaw opening in the lower jaw assembly as said upper and lower jaw assemblies moves along said sealing run, said heat sealing and cutting member pressing the overlapping portions of the upper and lower webs against said face portion on the upper jaw assembly during severing of the overlapping portion of the webs.

Claim 6

An apparatus according to claim 4 wherein said face portion is of resilient and deformable material.

Claim 7

An apparatus for wrapping articles according to claim 4 wherein said heat sealing and cutting member is rotatably supported on generally horizontal shaft means extending crosswise of said article path, means supporting said shaft means for limited vertical shifting movement, and means yieldably biasing said shaft means upwardly to yieldably urge said heat sealing and cutting member to a level slightly above said pair of clamping jaws on the lower jaw assembly.

Claim 8

An apparatus for wrapping articles according to claim 6 wherein said face portion is resilient.

Claim 9

In an apparatus for wrapping articles in heat sealable sheet material as they move along an article path including upper and lower endless jaw conveyor means respectively having at least one upper and one lower jaw assembly spaced therealong and extending generally horizontally crosswise of the article path, said upper and lower endless conveyor means respectively having generally horizontal Lower and upper sections thereof extending forwardly along the article path in a sealing run in which one upper and one lower jaw assembly move in opposed pairs along the sealing run, means for supporting end sections of upper and lower webs respectively above and below the article path, the ends of which webs have previously been joined to form a curtain of the material extending crosswise of the article path adjacent the inlet end of said sealing run, means for advancing an article along the article path into the curtain to draw the curtain along the top and bottom of the article and to position the article in front of a pair of said jaw assemblies as they move toward the inlet end of said sealing run, the improvement wherein said lower jaw assembly includes a pair of lower clamping jaw members extending crosswise of the article path and spaced apart in a direction lengthwise of the article path to define a jaw opening therebetween, means for guiding said upper and lower jaw assemblies as they move along the sealing run with an upper jaw assembly clamping overlapping portions of the upper and lower webs to the pair of lower clamping jaw members of a lower jaw assembly, a generally horizontal heat sealing and cutting member extending crosswise of said article path and mounted on shaft means for rotation about an axis paralleling said heat sealing and cutting member for movement in a closed loop course extending generally tangent to said upper section of the lower conveyor means in a zone intermediate the ends of said sealing run, and means for rotating said sealing and cutting member in timed relation with said lower conveyor means along said closed loop course sequentially into the jaw opening in said lower jaw assembly as it moves past said intermediate zone to sever and seal overlapping portions of the upper and lower webs at opposite sides of the severance and then out of said lower jaw opening before the upper and lower jaw assemblies reach the end of the sealing run to allow the sealed webs to cool.

Claim 10

In an apparatus for wrapping articles in heat sealable sheet material as they move along an article path including upper and lower endless jaw conveyor means respectively having at least one upper and one lower jaw assembly spaced therealong and extending generally horizontally crosswise of the article path, said upper and lower endless conveyor means respectively having generally horizontal Lower and upper sections thereof extending forwardly along the article path in a sealing run in which one upper and one lower jaw assembly move in opposed pairs along the sealing run, means for supporting end sections of upper and lower webs respectively above and below the article path, the ends of which webs have previously been joined to form a curtain of the material extending crosswise of the article path adjacent the inlet end of said sealing run, means for advancing an article along the article path into the curtain to draw the curtain along the top and bottom of the article and to position the article in front of a pair of said jaw assemblies as they move toward the inlet end of said sealing run, the improvement wherein said lower jaw assembly includes a pair of lower clamping jaw members extending crosswise of the article path and spaced apart in a direction lengthwise of the article path to define a jaw opening therebetween, means for guiding said upper and lower jaw assemblies as they move along the sealing run with an upper jaw assembly clamping overlapping portions of the upper and lower webs to the pair of lower clamping jaw members of a lower jaw assembly, a generally horizontal heat sealing and cutting member extending crosswise of said article path and mounted on shaft means for rotation about an axis paralleling said heat sealing and cutting member for movement in a closed loop course extending generally tangent to said upper section of the lower conveyor means in a zone intermediate the ends of said sealing run, and means for rotating said sealing and cutting member in timed relation with said lower conveyor means along said closed loop course sequentially into the jaw opening in said lower jaw assembly as it moves past said intermediate zone to sever and seal overlapping portions of the upper and lower webs at opposite sides of the severance and then out of said lower jaw opening before the upper and lower jaw assemblies reach the end of the sealing run to allow the sealed webs to cool.

Claim 11

An apparatus for wrapping articles according to claim 8 wherein said clamping jaw members of the lower jaw assembly have upper faces cooperable with an upper jaw assembly to clamp overlapping portions of the web therebetween and adjacent side faces which diverge outwardly from the adjacent edges of said upper faces whereby said jaw opening is relatively narrow adjacent said upper faces and increases in width in a direction away from said upper faces of the lower jaw member to facilitate movement of the sealing and cutting member into and out of said jaw opening.

Claim 12

An apparatus for wrapping articles according to claim 8 wherein said upper jaw assembly has a resilient portion spanning the space between the lower jaw members of a lower jaw assembly during movement along the sealing run.

Claim 13

An apparatus for wrapping articles according to claim 10 wherein said sealing and cutting member has a generally wedge shaped cross-section providing a relatively sharp sealing and cutting edge at its radially outer edge.

Claim 14

An apparatus for wrapping articles according to claim 10 wherein said shaft means is supported for limited vertical movement, and means yieldably biasing said shaft means upwardly to a level slightly above the level of said clamping jaw members on said lower jaw assemblies.

Claim 15

An apparatus for wrapping articles according to claim 8 wherein upper and lower conveyors respectively have at least two of said upper and lower jaw assemblies spaced therealong and said sealing and cutting member has a radially outer edge spaced from the axis of said shaft means a distance such that said closed loop course has a length approximating the spacing between adjacent lower jaw assemblies on the lower conveyor means.

Claim 16

An apparatus according to claim 8 including a plurality of article support rollers on said lower conveyor means intermediate adjacent ones of said lower jaw assemblies.