Defroster arrangement in a refrigerating showcase

Abstract From the Canadian patent

An improved defroster arrangement is equipped in a known refrigerating showcase provided with an inside duct for circulating a refrigerated air flow to refrigerate the interior of the showcase and an outside duct for circulating a low temperature air flow to prevent a temperature rise of the refrigerated air flow in juxtaposition. The improvements exist in the provision of communication means between said inside and outside ducts, and gate means for opening and closing said communication means. Upon defrosting the gate means is actuated to communicate the inside and outside ducts to each other through the communication means and also to block the path through the outside duct between the …