Method and apparatus for wrapping articles

Claim 1

A method of wrapping articles in webs of heat sealable material as the articles move along an article path, comprising: continuously moving a plurality of upper jaws in spaced succession along a closed loop course first downwardly along an inlet run; then forwardly along a sealing run a distance greater than the spacing between adjacent upper jaws; then upwardly along an outlet run; and finally rearwardly in a return run above the article path back to the first run, moving a plurality of spaced lower jaws along the sealing run in opposed relation to respective ones of the upper jaws, supporting end sections of first and second webs of material respectively above and below the article path, the ends of which webs have previously been joined to form a curtain across the article path adjacent the inlet end of the sealing run, advancing articles along the path into the curtain and below one of the upper jaws as it moves along the inlet run to a position in front of that upper jaw for advance therewith along the sealing run, sensing the presence or absence of an article in front of each upper jaw as it begins movement along the sealing run, relatively shifting the upper and lower jaws of an opposed pair into clamping engagement with a curtain therebetween when an article is present in front of that pair of jaws as they begin movement along the sealing run and maintaining that pair of jaws in clamping engagement with the curtain behind the article as that pair of jaws advance along the sealing run a distance greater that the spacing between adjacent upper jaws, relatively shifting the upper and lower jaws of an opposed pair to a position out of clamping engagement with the curtain therebetween when no article is present in front of that opposed pair of jaws as they begin movement along the sealing run, severing the overlapping portions of the curtain and sealing the overlapping portions along opposite sides of the severance when the curtain is clamped between an opposed pair of the upper and lower jaws, and retracting the curtain after all of the pairs of jaws along the sealing run are moved out of clamping engagement with the curtain.

Claim 2

A method of wrapping articles in webs of heat sealable material as the articles move along an article path, comprising: continuously moving a plurality of upper jaws in spaced succession along a closed loop course first downwardly along an inlet run; then forwardly along a sealing run a distance greater than the spacing between adjacent upper jaws; then upwardly along an outlet run; and finally rearwardly in a return run above the article path back to the first run, moving a plurality of spaced lower jaws along the sealing run in opposed relation to respective ones of the upper jaws, supporting end sections of first and second webs of material respectively above and below the article path, the ends of which webs have previously been joined to form a curtain across the article path adjacent the inlet end of the sealing run, advancing articles along the path into the curtain and below one of the upper jaws as it moves along the inlet run to a position in front of that upper jaw for advance therewith along the sealing run, sensing the presence or absence of an article in front of each upper jaw as it begins movement along the sealing run, relatively shifting the upper and lower jaws of an opposed pair into clamping engagement with a curtain therebetween when an article is present in front of that pair of jaws as they begin movement along the sealing run and maintaining that pair of jaws in clamping engagement with the curtain behind the article as that pair of jaws advance along the sealing run a distance greater that the spacing between adjacent upper jaws, relatively shifting the upper and lower jaws of an opposed pair to a position out of clamping engagement with the curtain therebetween when no article is present in front of that opposed pair of jaws as they begin movement along the sealing run, severing the overlapping portions of the curtain and sealing the overlapping portions along opposite sides of the severance when the curtain is clamped between an opposed pair of the upper and lower jaws, and retracting the curtain after all of the pairs of jaws along the sealing run are moved out of clamping engagement with the curtain.

Claim 5

A method of wrapping articles in webs of heat sealable material as the article move along an article path comprising: continuously moving a plurality of upper jaws in spaced succession along a closed loop course first downwardly along an inlet run; then forwardly along a sealing run; then upwardly along an outlet run; and finally rearwardly in a return run above the article path, moving a plurality of spaced lower jaws along the sealing run in opposed relation to respective ones of the upper jaws, guiding the upper and loweR jaws respectively along upper and lower guides as they move along the sealing run a distance greater than the spacing between adjacent upper jaws, supporting end sections of first and second webs of material respectively above and below the article path, the ends of which webs have previously been joined to form a curtain across the article path, advancing a series of articles in succession along the path into the curtain and below an upper jaw as it moves along the inlet run to a position in front of an upper jaw for advance therewith along the sealing run, sensing said advance of articles into the curtain to a position in front of an upper jaw, relatively shifting the upper and lower guides toward each other when the first article in the series is advanced to the sealing run to guide the upper and lower jaws of an opposed pair in clamping engagement with the webs as the jaws move along the sealing run and relatively shifting the guides away from each other when the last article in the series reaches the outlet end of the sealing run to release the upper and lower jaws from clamping engagement with the curtain, severing overlapping portions of the curtain and sealing overlapping portions of the curtain at opposite sides of the severance when the overlapping portions of the curtain are clamped between the jaws of an opposed pair, and retracting the curtain after all of the opposed pairs of upper and lower jaws along the sealing run are released from clamping engagement with the curtain.

Claim 6

A method of wrapping articles in webs of heat sealable material as the article move along an article path comprising: continuously moving a plurality of upper jaws in spaced succession along a closed loop course first downwardly along an inlet run; then forwardly along a sealing run; then upwardly along an outlet run; and finally rearwardly in a return run above the article path, moving a plurality of spaced lower jaws along the sealing run in opposed relation to respective ones of the upper jaws, guiding the upper and loweR jaws respectively along upper and lower guides as they move along the sealing run a distance greater than the spacing between adjacent upper jaws, supporting end sections of first and second webs of material respectively above and below the article path, the ends of which webs have previously been joined to form a curtain across the article path, advancing a series of articles in succession along the path into the curtain and below an upper jaw as it moves along the inlet run to a position in front of an upper jaw for advance therewith along the sealing run, sensing said advance of articles into the curtain to a position in front of an upper jaw, relatively shifting the upper and lower guides toward each other when the first article in the series is advanced to the sealing run to guide the upper and lower jaws of an opposed pair in clamping engagement with the webs as the jaws move along the sealing run and relatively shifting the guides away from each other when the last article in the series reaches the outlet end of the sealing run to release the upper and lower jaws from clamping engagement with the curtain, severing overlapping portions of the curtain and sealing overlapping portions of the curtain at opposite sides of the severance when the overlapping portions of the curtain are clamped between the jaws of an opposed pair, and retracting the curtain after all of the opposed pairs of upper and lower jaws along the sealing run are released from clamping engagement with the curtain.

Claim 9

An apparatus for wrapping articles in heat sealable sheet material as they move along an article path comprising: upper and lower endless conveyor means each having a plurality of sealing jaws spaced therealong and arranged to have adjacent sections extend forwardly along the article path in a sealing run having a length greater than the spacing between adjacent sealing jaws and with the sealing jaws on the upper and lower conveyor means moving in opposed pairs along said sealing run, means for supporting end sections of two webs at opposite sides of the article path, the ends of which webs have previously been joined to form a curtain of the material 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 sealing jaws as they move toward the inlet end of said sealing run, article sensing means for sensing the presence or absence of an article in front of the pairs of sealing jaws as they move along the sealing run, and jaw operating means operative when an article is present in front of a pair of sealing jaws for relatively shifting the sealing jaws of that pair toward each other into clamping engagement with overlapping portions of the curtain as that pair of sealing jaws move along said sealing run a distance greater than the spacing between adjacent sealing jaws, said jaw operating means being operative in the absence of an article in front of a pair of sealing jaws at the inlet end of the sealing run for relatively moving the sealing jaws of that pair away from each other out of clamping engagement with overlapping portions of the curtain, means on said sealing jaws for severing and sealing tHe curtain along opposite sides of the severance line when the curtain is clamped between the pairs of sealing jaws, and means for retracting the curtain after all of the pairs of sealing jaws are moved out of clamping engagement with the curtain.

Claim 10

An apparatus for wrapping articles in heat sealable sheet material as they move along an article path comprising: upper and lower endless conveyor means each having a plurality of sealing jaws spaced therealong and arranged to have adjacent sections extend forwardly along the article path in a sealing run having a length greater than the spacing between adjacent sealing jaws and with the sealing jaws on the upper and lower conveyor means moving in opposed pairs along said sealing run, means for supporting end sections of two webs at opposite sides of the article path, the ends of which webs have previously been joined to form a curtain of the material 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 sealing jaws as they move toward the inlet end of said sealing run, article sensing means for sensing the presence or absence of an article in front of the pairs of sealing jaws as they move along the sealing run, and jaw operating means operative when an article is present in front of a pair of sealing jaws for relatively shifting the sealing jaws of that pair toward each other into clamping engagement with overlapping portions of the curtain as that pair of sealing jaws move along said sealing run a distance greater than the spacing between adjacent sealing jaws, said jaw operating means being operative in the absence of an article in front of a pair of sealing jaws at the inlet end of the sealing run for relatively moving the sealing jaws of that pair away from each other out of clamping engagement with overlapping portions of the curtain, means on said sealing jaws for severing and sealing tHe curtain along opposite sides of the severance line when the curtain is clamped between the pairs of sealing jaws, and means for retracting the curtain after all of the pairs of sealing jaws are moved out of clamping engagement with the curtain.

Claim 13

An apparatus for wrapping articles in heat sealable material as they are advanced along an article path comprising: web support means for supporting end sections of two webs of said material respectively above and below the article path, the ends of which webs have previously been joined to form a curtain extending crosswise of said path, a lower endless type article conveyor means having an upper section extending forwardly from said curtain along said article path, an upper endless type jaw conveyor means disposed above said article conveyor means and supporting a plurality of jaws for movement in a closed loop course including a lower section extending forwardly adjacent said upper section of said article conveyor means in a sealing run therewith, first and second guide means for respectively guidably supporting said upper run of said article conveyor means and said lower run of said jaw conveyor means during movement along said sealing run a distance greater than the spacing between adjacent pairs of jaws, means for advancing an article to be wrapped into said curtain and onto said article conveyor means to draw the curtain of material along the lead side and along the top and bottom of the article advanced onto the article conveyor means, means for sensing an article advanced onto said article conveyor means, guide moving means responsive to said sensing means operative when an article is advanced onto said article conveyor means to relatively move said first and second guide means toward each other to a sealing position in which a jaw on the upper jaw conveyor means is operative to clamp overlapping portions of the webs to said article conveyor means, said guide moving means being operative in the absence of an article on said article conveyor means to relatively move said first and second guide means away from each other to a release position in which a sealing jaw on the jaw conveyor means releases the overlapping portions of the webs from clamping engagement with the article conveyor means, means for severing overlapping portions of the webs and for heat sealing the overlapping portions along opposite sides of the line of severance while the overlapping portions are clamped to the article conveyor means, and means for retracting at least one of said webs after the overlapping portions of the web are released.

Claim 14

An apparatus for wrapping articles in heat sealable material as they are advanced along an article path comprising: web support means for supporting end sections of two webs of said material respectively above and below the article path, the ends of which webs have previously been joined to form a curtain extending crosswise of said path, a lower endless type article conveyor means having an upper section extending forwardly from said curtain along said article path, an upper endless type jaw conveyor means disposed above said article conveyor means and supporting a plurality of jaws for movement in a closed loop course including a lower section extending forwardly adjacent said upper section of said article conveyor means in a sealing run therewith, first and second guide means for respectively guidably supporting said upper run of said article conveyor means and said lower run of said jaw conveyor means during movement along said sealing run a distance greater than the spacing between adjacent pairs of jaws, means for advancing an article to be wrapped into said curtain and onto said article conveyor means to draw the curtain of material along the lead side and along the top and bottom of the article advanced onto the article conveyor means, means for sensing an article advanced onto said article conveyor means, guide moving means responsive to said sensing means operative when an article is advanced onto said article conveyor means to relatively move said first and second guide means toward each other to a sealing position in which a jaw on the upper jaw conveyor means is operative to clamp overlapping portions of the webs to said article conveyor means, said guide moving means being operative in the absence of an article on said article conveyor means to relatively move said first and second guide means away from each other to a release position in which a sealing jaw on the jaw conveyor means releases the overlapping portions of the webs from clamping engagement with the article conveyor means, means for severing overlapping portions of the webs and for heat sealing the overlapping portions along opposite sides of the line of severance while the overlapping portions are clamped to the article conveyor means, and means for retracting at least one of said webs after the overlapping portions of the web are released.

Claim 19

An apparatus for wrapping articles in heat sealable sheet material as they are advanced along an article path comprising, a lower endless type article conveyor means having a plurality of spaced lower sealing jaws extending crosswise the article path and having an upper section extending forwardly along said article path, an upper endless type jaw conveyor means having a plurality of upper sealing jaws extending crosswise of the article path and having a lower section extending forwardly along the article path above the upper section of the article conveyor means to have a sealing run therewith, said upper sealing jaws being spaced apart a distance corresponding to the spacing between the lower jaws and being arranged to move in opposed relation therewith along said sealing run, first and second guides for respectively guiding said upper and lower sealing jaws during movement along said sealing run a distance greater than the spacing between adjacent sealing jaws, means for supporting a curtain of material to extend crosswise of the article path adjacent the inlet end of said article conveyor means, means for advancing articles into said curtain and onto said article conveyor means to draw the curtain along the top and bottom of the article advanced onto the article conveyor means, means for driving the upper and lower conveyor means in timed relation to move the upper and lower jaws forwardly in opposed registry along said sealing runs thereof, sensing means for sensing an article advanced onto said article conveyor means, and guide moving means responsive to said sensing means for relatively moving said first and second guides toward and away from each other between an operating position in which the guides support the upper and lower sealing jaws in clamping arrangement with overlapping portions of a web at the top side of an article during forward movement of the jaws along the sealing run and a release position releasing the upper and lower sealing jaws from clamping engagement with the webs in the absence of an article on the article conveyor means, means on the sealing jaws for severing overlapping portions of the webs and for heat sealing the overlapping portions along opposite sides of the line of severance while the overlapping portions are clamped between the sealing jaws, and means for retracting at least one of said webs after the guides are moved to their release position.

Claim 20

An apparatus for wrapping articles in heat sealable sheet material as they are advanced along an article path comprising, a lower endless type article conveyor means having a plurality of spaced lower sealing jaws extending crosswise the article path and having an upper section extending forwardly along said article path, an upper endless type jaw conveyor means having a plurality of upper sealing jaws extending crosswise of the article path and having a lower section extending forwardly along the article path above the upper section of the article conveyor means to have a sealing run therewith, said upper sealing jaws being spaced apart a distance corresponding to the spacing between the lower jaws and being arranged to move in opposed relation therewith along said sealing run, first and second guides for respectively guiding said upper and lower sealing jaws during movement along said sealing run a distance greater than the spacing between adjacent sealing jaws, means for supporting a curtain of material to extend crosswise of the article path adjacent the inlet end of said article conveyor means, means for advancing articles into said curtain and onto said article conveyor means to draw the curtain along the top and bottom of the article advanced onto the article conveyor means, means for driving the upper and lower conveyor means in timed relation to move the upper and lower jaws forwardly in opposed registry along said sealing runs thereof, sensing means for sensing an article advanced onto said article conveyor means, and guide moving means responsive to said sensing means for relatively moving said first and second guides toward and away from each other between an operating position in which the guides support the upper and lower sealing jaws in clamping arrangement with overlapping portions of a web at the top side of an article during forward movement of the jaws along the sealing run and a release position releasing the upper and lower sealing jaws from clamping engagement with the webs in the absence of an article on the article conveyor means, means on the sealing jaws for severing overlapping portions of the webs and for heat sealing the overlapping portions along opposite sides of the line of severance while the overlapping portions are clamped between the sealing jaws, and means for retracting at least one of said webs after the guides are moved to their release position.