Rapidly deployable modular shelter system
A purlin connection assembly including a purlin, a frame segment and a spring. The purlin has a protrusion that is receivable in a first end of a slot of the frame segment. The purlin is slidable to a smaller second end of the frame segment. Locking engagement is achieved in a direction parallel to the frame segment by a pair of push buttons projecting from the frame segment that flank the purlin when in the second end, and in a direction perpendicular to the frame segment by constraining of a flared head of the protrusion in an interior of the frame segment when in the second end. The push buttons are part of a spring compressingly disposed in the interior of the frame segment, wherein the first button and the second button are biased to extend outwardly through button holes of the frame segment.
1. A purlin connection assembly comprising:
a purlin comprising a protrusion, the protrusion comprising a neck and a flared head;
a frame segment comprising
an interior,
a slot comprising a first end and a second end, wherein a height of the first end is at least as great as a height of the flared head, and wherein a height of the second end is less than the height of the flared head and at least as great as a height of the neck;
a first button hole and a second button hole, the first button hole vertically aligned with the first end, a distance separating the first button hole and the second button hole being greater than a width of the purlin; and
a spring comprising a first button and a second button, the spring compressingly disposed in the interior of the frame segment, wherein the first button and the second button are biased to extend outwardly through the first button hole and the second button respectively to project out of the frame segment, and wherein the first button and the second button are rigidly connected whereby depressing the second button effects inward retraction of the first button.
2. The assembly of claim 1 wherein the spring comprises a V-shape with two arms wherein the second button is located relatively proximal along the arm and the first button is located relatively distal along the arm.
3. The assembly of claim 2 wherein, on an opposite side of the frame segment for attachment of a second purlin, the frame segment comprises a corresponding second slot and third and fourth button holes, and the spring comprises corresponding third and fourth buttons.
4. The assembly of claim 1 wherein the first end narrowingly tapers to the second end.
5. The assembly of claim 1 wherein a width of the slot is at least twice the width of the protrusion.
6. The assembly of claim 1 wherein the flared head and the neck of the protrusion form a T-shaped cross-section.
7. A method of connecting and disconnecting a purlin and a frame segment, the method comprising:
a. providing a purlin connection assembly according to claim 1 ;
b. to attach the purlin to the frame segment:
i. directing the protrusion of the purlin through the first end of the slot of the frame segment, whereby an end face of the purlin abuts and depresses the first button of the spring;
ii. sliding the purlin laterally to engage the protrusion with the second end of the slot, whereby the first button is released and reverts to outward protrusion from the first button hole of the frame segment, whereby the purlin is locked in a direction parallel to the frame segment by the first and second buttons, and locked in a direction perpendicular to the frame segment by the flared head being constrained in the interior of the frame segment by the second end of the frame segment;
c. to detach the purlin from the frame segment;
i. depressing the second button to cause the first button to retract from the first button hole;
ii. sliding the purlin laterally from the second end to the first end; and
iii. pulling the purlin away from the frame segment.