Osprey Packs, Inc., a Colorado-based backpack manufacturer, has been granted U.S. Patent No. 12,336,619 for a modular backpack system incorporating a 3D printed lumbar pad designed to improve load distribution, airflow, and anatomical compatibility. Filed in January 29, 2021 and Granted on June 24, 2025 by the United States Patent and Trademark Office (USPTO), the patent describes how variable-stiffness structures and digital customization workflows can enhance user-specific fit in technical packs.
The lumbar pad uses a monolithic lattice structure composed of beams and nodes that create hexagonal and other polygonal cells. This internal geometry is fabricated using additive manufacturing and bonded to a perimeter ribbon base that anchors the component to the backpack. Two shape variants are documented: one with rounded corners and convex curvature, and another with angular sides. Both versions include elongated ventilation cutouts and are shaped like isosceles trapezoids. The pads are designed to mount onto either rigid foam framesheets or tensioned mesh back panels, and integrate with shoulder harnesses and hip belts.
Stiffness zones within the pad are arranged according to location and thickness. Pressure maps (FIGS. 7 and 8) show a center region with the highest resistance, surrounded by concentric boundary areas with progressively lower hardness values. Hardness is defined by the force required to compress the pad 40% of its depth using a 28.5 mm diameter instrument. Sample measurements across zones and thicknesses range from 17.4 newtons to 50.9 newtons. One configuration shows an increase in hardness from top to bottom, while another displays a gradient from outer edge toward the center.
Up to twelve lattice layers can be included. Interior cells are typically regular hexagons that align vertically across layers, while edge cells may vary to conform to the pad’s perimeter. At least 80 percent of cells that line up between layers have equal numbers of sides in several embodiments. The entire structure is formed from a single flexible polymer in a continuous 3D print process. Surface perforations and cutouts enhance ventilation and drying, while also reducing sweat accumulation during exertion.
Osprey’s system allows users to input body dimensions and desired load capacity through a website. These parameters are used to fabricate components such as lumbar pads, shoulder harnesses, hip belts, and back panels using the same lattice-based structure. Each part is tailored to user profiles through adjustments in cell alignment, number of layers, and material density. Attachments include glue zones, lugs, stitching, fusion welding, and sonic welds. FIG. 6 illustrates glue contact points and anchoring lugs on the upper surface of one variant.
Materials specified in the patent are abrasion-resistant polymers that remain flexible across a temperature range from –40 to 100°C. These polymers are UV-stable, sweat- and salt-resistant, and designed to function under loads up to 40 kilograms. Surface textures are lightly textured and perforated to support air circulation and moisture evaporation. The design is compliant with REACH, Proposition 65, and Bluesign standards.
Some configurations include overhanging outer edges and recessed center channels to accommodate different back panel types. Others include multiple elongated vertical holes to further improve airflow. Anatomical shaping is achieved through curvature and padding gradients mapped to typical lumbar anatomy. The same principles apply to shoulder harness and hip belt interfaces, which may also be fabricated with lattice interiors and graded stiffness.
Figures in the patent illustrate several complete backpacks, including models with foam-based back panels and others with suspended mesh. Variants include modular systems with interchangeable lumbar pads and load-bearing elements. In all cases, lattice configurations remain monolithic, with no internal adhesives or stitched seams within the lattice body itself.
While the patent does not reference a specific product release, the technical framework supports mass customization through additive manufacturing. The integration of airflow, mechanical zonal resistance, and anatomical conformity into a single component enables production of performance-oriented backpacks that match user-specific ergonomic profiles.
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