Method and apparatus for making sealed packages for spreadable products

An apparatus for the high speed production of sealed packages for the storing, shipping and handling of individual service portions of a spreadable product which support said spreadable product for use after said packages are opened, said apparatus adapted to operate in continuous uninterrupted synchronized movement with means for positioning said individual service portions of spreadable product on the approximate center of a substantially flat, relatively stiff base member having margins surrounding said spreadable product, comprising:

• (a) a continuous supply of indefinite length, flexible sheet material;
• (b) a continuously driven rotatably mounted drum having a plurality of shaping stations on the periphery thereof;
• (c) means for continuously feeding and consecutively cutting individual predetermined lengths of said sheet material in synchronization with the rotary movement of said drum;
• (d) guide means for directing and continuously feeding each individual predetermined cut length of said sheet material to the peripheral surface of said drum in centered register with each of said shaping stations;
• (e) each of said shaping stations including
• a plurality of walls forming and substantially completely surrounding a shaping cavity, and
• means for creating a vacuum in said walls substantially completely about the perimeter of said shaping cavity,
• said vacuum means adapted to engage the margin portions of said individual predetermined cut length of said sheet material at said shaping station and slidably retain said cut length of material against said walls substantially completely about the perimeter of said shaping cavity in a substantially flat configuration in centered register over said shaping cavity;
• (f) first tamper means including a tamper head to consecutively press each of said slidably retained individual cut lengths of said sheet material into said shaping cavity at each of said shaping stations to press said sheet material into a three-dimensional cover member without stretching of said sheet material and to thereafter withdraw from the formed three-dimensional cover member,
• said vacuum means retaining said formed cover member in said three-dimensional shape within said shaping cavity upon withdrawal of said tamper head from said shaping cavity;
• (g) said three-dimensional cover member having
• a substantially flat center portion,
• a substantially flat margin portion extending laterally outwardly from said center portion in a separate plane generally parallel thereto, and
• side walls connecting said center portion to said margin portion;
• (h) means continuously driving said first tamper means in synchronization with the rotary movement of said drum so that the path followed by said tamper head as it travels into and out of said shaping cavity is always maintained along a radial line extending through the axis of rotation of said drum and the center of said shaping cavity and said tamper head is maintained substantially perpendicular to said radial line while forming said sheet material into said three-dimensional cover member,
• said tamper head consecutively traveling into and out of each of said shaping cavities during constant rotation of said drum;
• (i) said vacuum means slidably retains said margin portions of said sheet material on the peripheral surface of said drum while said tamper head presses the remaining portions thereof into said shaping cavity and thereafter holds said margin portion of the formed cover member in a fixed position thereby maintaining the three-dimensional shape of said cover member upon withdrawal of said tamper head from said shaping cavity;
• (j) high speed means continuously transporting said base members at uniformly spaced intervals on a path tangentially adjacent the peripheral surface of said drum in synchronization with the rotation of said drum so that each of said consecutively shaped three-dimensional cover members is transported by said drum into moving register with each of said moving base members,
• said moving register between said cover member and said base member locating said center portion of said cover member over said spreadable product carried by said base member with no substantial deformation of said spreadable product;
• (k) means for releasing said cover member from said drum upon being rotated into moving register with said moving base member,
• said release means comprising means for breaking said vacuum while substantially simultaneously compressing certain of said margin portion of said cover member onto certain of said margins on said base member;
• and
• (l) means for removably sealably adhering said margin portion of said released cover member to said margins on said base member upon compression thereto to sealingly enclose said spreadable product therebetween.