IP Library Granted Patent US 12,552,322
Granted Patent B2
US 12,552,322 · App. 18/081,282 · Granted Feb 17, 2026

Entry steps with center stringer

Inventors: Tyler Nine (Osceola, IN); Brandon Joseph Williams (Warsaw, IN); Nicholas Cornett (Granger, IN); Bryan J. Roth (Topeka, IN)
Assignee: LIPPERT COMPONENTS, INC.
B60R3/02
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,552,322
App. No.
18/081,282
Granted
Feb 17, 2026
Kind
B2
Abstract

A stair assembly suited for a vehicle entrance includes a plurality of step treads, each of the step treads having a tread width, and a stringer to which the plurality of step treads are secured. The stringer is positioned within the tread width.

Claims (35)

1 . A stair assembly comprising:

a plurality of step treads, each of the step treads having a tread width;

a stringer to which the plurality of step treads are secured, wherein the stringer is positioned within the tread width; and

a threshold plate secured to the stringer and selectively attachable to an entry threshold.

2 . A stair assembly according to claim 1 , wherein the stringer is centrally positioned within the tread width.

3 . A stair assembly according to claim 1 , wherein the stringer is a single stringer and is sole support for the step treads.

4 . A stair assembly according to claim 1 , wherein the threshold plate comprises a hinge such that the stair assembly is pivotable between a stowed position and a use position.

5 . A stair assembly according to claim 4 , wherein the threshold plate comprises a connecting section attachable to the entry threshold and a support plate connected to the stringer, the stair assembly further comprising a latching assembly configured to be secured the stair assembly in the stowed position, the latching assembly including a propping plate connected at one end to the connecting section and selectively connectable at an opposite end to a vertical support component coupled with the support plate.

6 . A stair assembly according to claim 5 , wherein the latching assembly further comprises at least one connecting cable connected between the connecting section and the support plate.

7 . A stair assembly according to claim 5 , wherein the propping plate is pivotable between a connected position engaging the support plate and a disconnected position disengaged from the support plate, wherein in the disconnected position, the propping plate lays flat against the connecting section.

8 . A stair assembly according to claim 7 , wherein the propping plate is biased toward the disconnected position by a spring.

9 . A stair assembly according to claim 4 , further comprising an adapter fixed to the threshold plate and securable to the stringer.

10 . A stair assembly according to claim 9 , wherein a top step tread of the plurality of step treads is secured to the stringer via bolts, and wherein the adapter is secured to the stringer with the bolts.

11 . A stair assembly according to claim 1 , further comprising a plurality of tread mounting brackets respectively connected between the step treads and the stringer.

12 . A stair assembly according to claim 11 , wherein the stringer comprises a bracket connect section and a leg section, the bracket connect section having an outer shape, and wherein the tread mounting brackets comprise flanges that are shaped in complement to the outer shape.

13 . A stair assembly according to claim 12 , wherein the flanges of the tread mounting brackets are secured to the stringer via bolts.

14 . A stair assembly according to claim 11 , wherein each of the tread mounting brackets comprises a support structure connected to the tread mounting brackets, the support structure comprising a triangular frame from a side profile with a first leg that extends across a bottom surface of the step treads, a second leg as an angled plate that extends from a front of the step treads and is connected to the tread mounting brackets, and a third leg fixed to the tread mounting brackets.

15 . A stair assembly according to claim 1 , wherein the step treads comprise a flat top with bent edges to create downward flanges on a front, a back, and sides of each of the step treads.

16 . A stair assembly according to claim 1 , wherein the step treads are curved around the stringer.

17 . A stair assembly according to claim 1 , wherein the stringer comprises a bracket connect section and a leg section, the stair assembly further comprising a support leg selectively positionable in the leg section.

18 . A stair assembly according to claim 17 , further comprising a stabilizing footpad secured at a distal end of the support leg.

19 . A stair assembly according to claim 1 , wherein the stringer comprises a bracket connect section and a leg section, and wherein the stair assembly further comprises an electrical wire extending through one of the bracket connect section and the leg section.

20 . A stair assembly according to claim 1 , wherein the stringer comprises a bracket connect section and a leg section, wherein the bracket connect section comprises a first extruded hollow tube and the leg section comprises a second extruded hollow tube, the bracket connect section being fixed to the leg section.

21 . A stair assembly comprising:

a plurality of step treads, each of the step treads having a tread width; and

a stringer to which the plurality of step treads are secured, wherein the stringer is positioned within the tread width,

wherein the stringer comprises a bracket connect section and a leg section, wherein the bracket connect section and the leg section are integrated as a one-piece extrusion.

22 . A stair assembly for a vehicle entrance, the stair assembly comprising:

a plurality of step treads, each of the step treads having a tread width;

a stringer to which the plurality of step treads are secured, wherein the stringer is positioned within the tread width; and

a threshold plate secured to the stringer and selectively attachable to the vehicle entrance, wherein the threshold plate comprises a hinge such that the stair assembly is pivotable between a stowed position and a use position.

23 . A stair assembly according to claim 22 , wherein the stringer comprises a bracket connect section and a leg section, wherein the bracket connect section and the leg section are separately extruded and connected or are integrated as a one-piece extrusion.

24 . A stair assembly according to claim 22 , further comprising a latching assembly configured to secure the stair assembly in the stowed position.

25 . A stair assembly according to claim 24 , wherein the threshold plate comprises a connecting section attachable to the vehicle entrance and a support plate connected to the stringer, and wherein the latching assembly comprises a propping plate connected at one end to the connecting section and selectively connectable at an opposite end to a vertical support component fixed to the support plate.

26 . A stair assembly according to claim 25 , wherein the latching assembly further comprises at least one connecting cable connected between the connecting section and the support plate.

Assignments (2)
SECURITY INTEREST Recorded Mar 25, 2025
From: LIPPERT COMPONENTS, INC.; CURT MANUFACTURING, LLC; FURRION, LLC; FURRION LTD; INNOVATIVE DESIGN SOLUTIONS, INC.; KASPAR RANCH HAND EQUIPMENT, LLC; LIPPERT COMPONENTS MANUFACTURING, INC.; TAYLOR MADE GROUP, LLC
To: JPMORGAN CHASE BANK, N.A.
Reel/Frame 070719/0650 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 14, 2022
From: NINE, TYLER; WILLIAMS, BRANDON JOSEPH; CORNETT, NICHOLAS; ROTH, BRYAN J.
To: LIPPERT COMPONENTS, INC.
Reel/Frame 062091/0628 →
Continuity (2)
Provisional Application 63289185 · Dec 14, 2021
Related Publication 20230182642A1 · Jun 15, 2023
References Cited (19)
US 3033309A · Fugere · 1962 [cited by applicant]
US D315134S · Springer · 1991 [cited by applicant]
US 6354403B1 · Truckner et al. · 2002 [cited by applicant]
US 7144058B1 · Winter · 2006 [cited by applicant]
US 8261880B1 · Hop · 2012 [cited by applicant]
US 9539948B1 · Presley · 2017 [cited by examiner]
US 9903121B2 · Tompkins et al. · 2018 [cited by applicant]
US 20020088669A1 · Truckner et al. · 2002 [cited by applicant]
US 20070273123A1 · Wilson · 2007 [cited by applicant]
US 20120285028A1 · Atwood · 2012 [cited by applicant]
US 20160369514A1 · Grommet · 2016 [cited by applicant]
US 20170267181A1 · Hoffman et al. · 2017 [cited by applicant]
US 20170350134A1 · Tompkins et al. · 2017 [cited by applicant]
US 20180148936A1 · Tompkins et al. · 2018 [cited by applicant]
US 20200102788A1 · Byers et al. · 2020 [cited by applicant]
US 20210261060A1 · Schwarz · 2021 [cited by applicant]
US 20210261061A1 · Fuller et al. · 2021 [cited by applicant]
US 20230053207A1 · Roth · 2023 [cited by applicant]
International Search Report dated Apr. 28, 2023 issued in PCT International Patent Application No. PCT/US2022/052878, 4 pp. [cited by applicant]