Various disclosed embodiments include illustrative door assemblies, vehicles, and methods of assembling door assemblies. In an illustrative embodiment, a door assembly has a right horizontal track, a left horizontal track, a counterbalance assembly having a right end and a left end, a right connector plate, and a left connector plate. The right connector plate is configured to be connected to the right horizontal track and to the right end of the counterbalance assembly. The left connector plate is configured to be connected to the left horizontal track and to the left end of the counterbalance assembly.

A roll-up door (10) with slats (60) rolled on a reel (12) with spiral guides (32) that maintain a tangent between the reel (12) and the closure plane at the point of entry/exit so as to maintain a perpendicular entry and exit with the side guides (36) and reduce friction, increase speed, reduce noise and help keep self-aligning end caps tracking correctly. It can also eliminate hinges between slats and permit each slat to be removed independently, without disassembling the other slats.

A roll-up door (10) with slats (60) rolled on a reel (12) with spiral guides (32) that maintain a tangent between the reel (12) and the closure plane at the point of entry/exit so as to maintain a perpendicular entry and exit with the side guides (36) and reduce friction, increase speed, reduce noise and help keep self-aligning end caps tracking correctly. It can also eliminate hinges between slats and permit each slat to be removed independently, without disassembling the other slats.

A high speed roll door is movable between an open and a closed position at an opening of a building. The door includes a flexible curtain and a pair of side columns. Each side column provides an inner track to guide the curtain in vertical movement and restrain the curtain from lateral movement during deployment and retraction. The curtain further includes multiple cross bars supporting the flexible curtain from one of the pair of side columns to the other. Each of the cross bars further includes a first longitudinal bar sandwiching part of the curtain; and a second longitudinal bar pivotally connected to the first longitudinal bar. The hinge has an axis of rotation parallel to the first and the second longitudinal bars. At least a wheel is rotatably affixed to each end of the second longitudinal bar to engage the inner track of each of the side columns.

A high speed roll door is movable between an open and a closed position at an opening of a building. The door includes a flexible curtain and a pair of side columns. Each side column provides an inner track to guide the curtain in vertical movement and restrain the curtain from lateral movement during deployment and retraction. The curtain further includes multiple cross bars supporting the flexible curtain from one of the pair of side columns to the other. Each of the cross bars further includes a first longitudinal bar sandwiching part of the curtain; and a second longitudinal bar pivotally connected to the first longitudinal bar. The hinge has an axis of rotation parallel to the first and the second longitudinal bars. At least a wheel is rotatably affixed to each end of the second longitudinal bar to engage the inner track of each of the side columns.

A panel assembly including a panel that can be positioned in an opening, the panel including a plurality of locking members spaced apart along at least part of a length of and proximate to opposing longitudinal edges of the panel and a guide extending along either side of the opening, each guide including at least one locking flange extending along at least part of a length of the guide, wherein in use the panel is received in the guides so that the locking members selectively engage the flanges to limit lateral movement of the panel edges.

A panel assembly including a panel that can be positioned in an opening, the panel including a plurality of locking members spaced apart along at least part of a length of and proximate to opposing longitudinal edges of the panel and a guide extending along either side of the opening, each guide including at least one locking flange extending along at least part of a length of the guide, wherein in use the panel is received in the guides so that the locking members selectively engage the flanges to limit lateral movement of the panel edges.

A shutter for protecting an opening. The shutter comprising a plurality of horizontal curtain slats for covering the opening, wherein horizontal refers to a direction when viewing slats from a front surface, and wherein the curtain slats hang freely from a upper region of the opening; an upper transition slat movably affixed to a lower end of a first curtain slat; a lower transition slat movably affixed to an upper end of a second curtain slat; and a horizontal reinforcing member comprising at least an upper and a lower reinforcing slat, wherein the upper reinforcing slat is rotatably affixed to a lower end of the first transition slat and the lower reinforcing slat is rotatably affixed to an upper end of the second transition slat, and wherein the upper and lower reinforcing slats are rotatably joined.

A shutter for protecting an opening. The shutter comprising a plurality of horizontal curtain slats for covering the opening, wherein horizontal refers to a direction when viewing slats from a front surface, and wherein the curtain slats hang freely from a upper region of the opening; an upper transition slat movably affixed to a lower end of a first curtain slat; a lower transition slat movably affixed to an upper end of a second curtain slat; and a horizontal reinforcing member comprising at least an upper and a lower reinforcing slat, wherein the upper reinforcing slat is rotatably affixed to a lower end of the first transition slat and the lower reinforcing slat is rotatably affixed to an upper end of the second transition slat, and wherein the upper and lower reinforcing slats are rotatably joined.

A pet door system is provided including a casing configured to attach the pet door system to a building and a flexible door attached to the casing. In some embodiments, the door is segmented and comprises a plurality of interlocking segments that are rotatable with respect to each other. In some embodiments, the pet door system further includes a rotating cylinder attached to the flexible door and rotatably connected to the casing and a motor comprising a gear head, where the gear head is attached to the rotating cylinder, such that when the motor is activated, the gear head is rotatable in a first direction to wind the flexible door around the rotating cylinder. In some embodiments, the pet door system may be operated by a pet-worn collar and/or may be remotely controlled via a mobile device.