Helical conveyor food freezer

A food freezer comprising an insulated enclosure for maintaining temperatures below ambient temperatures therewithin,

• means forming an entrance and an exit in said enclosure,
• an endless conveyor belt for carrying products from said entrance to said exit throughout said enclosure,
• means for driving said conveyor belt so that said endless conveyor belt follows along an initial straight-line path section and then along an ascending helical path section, a second straight-line section, a descending helical path section and a third straight-line path section leading to said exit from said enclosure,
• cooling means for establishing a temperature within said enclosure sufficiently low to satisfactorily remove heat from products carried along said conveyor,
• said belt having a plurality of horizontal rods extending laterally across said belt which rods support a plurality of support surface-providing units, means interconnecting said rods so that the pitch between adjacent rods in said belt at the inner lateral edge of said belt remains constant during the transition from said straight-line path section to said helical path section whereas longitudinal expansion of the pitch between said rods occurs at the outer lateral edge of said belt,
• said conveyor belt driving means including two cylindrical cages supported for rotation about vertical axes, each said cage having a plurality of equidistantly spaced apart vertical drive elements located circumferentially around said cage,
• said drive elements having a radially and vertically extending drive surfaces, which are spaced apart on the same pitch as said pitch at the inner ends of the rods, and
• said rods having protruding heads at the laterally inner ends thereof, which heads are engaged by said drive surfaces to positively drive said belt throughout both its helical paths.

A food freezer comprising an insulated enclosure for maintaining temperatures below ambient temperatures therewithin,

• means forming an entrance and an exit in said enclosure,
• an endless conveyor belt for carrying products from said entrance to said exit throughout said enclosure,
• means for driving said conveyor belt so that said endless conveyor belt follows along an initial straight-line path section and then along at least one helical path section, with such helical path portion constituting a significant portion of said belt's total pathway,
• cooling means for establishing a temperature within said enclosure sufficiently low to satisfactorily remove heat from products carried along said conveyor,
• said belt having a plurality of horizontal rods extending laterally across said belt which rods are interconnected by means including a plurality of support surface-providing units, said interconnecting means being constructed so that, during change of belt orientation from said straight-line path section to said helical path section, the pitch between the inner ends of said rods remains constant whereas the pitch between the outer ends of said rods expands and being further constructed so that there is negligible longitudinal tension along the outer edge of said belt in said helical path configuration,
• said conveyor belt driving means including at least one cylindrical cage supported for rotation about a vertical axis, said cage having a plurality of equidistantly spaced apart vertical drive elements located circumferentially around said cage, each of said drive elements having at least one radially and vertically extending drive surface, and
• said rods having protruding heads at the laterally inner ends thereof, which heads are engaged by said drive surfaces to positively drive said belt throughout its helical path, whereby the inner edge of said conveyor belt is maintained in low tension throughout said helical path and generally along its entire length and said outer edge is subjected to negligible longitudinal tension.